PREFACE
This annual report reviews the research activities of the Laboratory of Advanced Scienceand Technology for Industry (LASTI) in the academic year of 2012 (April 2012 –March2013) including activities using a 1.5GeV synchrotron radiation facility “ NewSUBARU ”
and compact 15-MeV linac "LEENA" at the site of SPring-8. Other research activities of the
micro and nanoscale carried out energetically at CAST building.
Topics of the NewSUBARU research activities of this year are as follows. First isachievements of a small linear electron accelerator LEENA. This accelerator wasreconstructed and generation of

THz Smith-Purcell radiation was started. Second isdevelopments of LSI mask pattern observation system for extreme ultraviolet lithography(EUVL) using lensless scatterometry microscope. Third is a new irradiation hutch for gammaray beam source was added by collaboration with Konan University. The user use of gammaray beam of photon energy up to 76.3 MeV was started. Generating maximum gamma-ray
power was 0.33mW. Fourth is the top-up beam current of NewSUBARU was enhanced from
250 mA to 300 mA. This was achieved by longer lifetime as a result of an additional
installation and optimization of sextupole magnet families.
Furthermore, most of our research activities are being conducted in collaboration withindustries, government research institutes and other universities. NewSUBARU beamlines areintensively used by companies. We will continue to respond to the community’s demand byoffering new science and technologies.

Shuji Miyamoto
Director of LASTI
University of HyogoⅰＣＯＮＴＥＮＴＳ
PREFACE···················································································································································ⅰ

CONTENTS················································································································································

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CURRENT STATUS OF NewSUBARU
NewSUBARU Storage Ring ······················································································································
Beamlines ·················································································································································

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ORGANIZATIONRESEARCH ACTIVITIES
Tentative Design Parameters of 1.5 GeV Injector Synchrotron for New SUBARU ·································
Calibration of Pyrgeometer by Blackbody Radiation with RMS method on New Steady State
Equation of Heat Transfer ·······················································································································
Preliminary Measurement of Solar and Atmosphere Radiations with a New Experimental Set-up of
Double Copper Plate Structure ·············································································································
Numerical Study on the Rayleigh Scattering of Solar Radiation ·····························································
Geometric Luminosity for the Angled Collision of Asymmetric Beams with Hourglass Effect ················
Observation of Smith-Purcell radiation in Terahertz regime at electron linear accelerator LEENA ······
Energy calibration of electron beams by laser Compton-scattering γ-rays at BL01 ·······························
NEXAFS Study on Hyperthermal Atomic Oxygen Beam Irradiation Effect on the Ti-containing DLC Film ····
Soft X-ray Irradiation Effect on Highly Hydrogenated Diamond-like Carbon Films ······························
Low-Temperature Activation of Boron in Si wafer by Soft X-ray Irradiation ··········································
Surface Modifications in Silica-Based Films by Undurator Radiation ····················································
Characterization BN Thin Film Deposited on Cemented Carbide using Soft X-ray Absorption Spectroscopy ·····
Spectral Recovery of Etching Damage by Soft X-ray Irradiation Observed in XAS spectra of TiO2 Thin Film ····
Modification of Electronic States of Multi-layer Graphenes by Ion Irradiation ······································
Fabrication of amino acid analysis chip using SR direct dry etching of PTFE ·······································
Powder Transport Direction Control Method by Using Drive Frequency of Surface AcousticWave ······
Fabrication of SERS Active Three-dimensional Silver Nanostructure ·····················································
Blood separation chip for automated biological analysis ········································································
Optimization of Surface Enhanced Raman Scattering Active Three- Dimensional Gold Nanostructure ····
Fabrication and characterization of three-dimensional type micro magneto-impedance sensor ············
Micro-Mirror Array Device for floating image manufactured by Synchrotron radiation ·······················
Broadband noise spectroscopy of a magnetic wire ··················································································
Defect Characterization of an EUV Mask using a Coherent EUV Scatterometry Microscope ················
Chemical Reaction Analysis of EUV CA Resist using SR AbsorptionSpectroscopy ··············
Plasma-Debris Sputter Resistant X-ray Mirror ·······················································································
Electronic Structure of theFluorinated Self-Assemble Monolayer by Photoemission and Absorption
Spectroscopy ············································································································································
Orientation evaluation of 3D-photoreactive liquid crystalline polymer structure fabricated by thermal
nanoimprinting ·········································································································································

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LIST OF PUBRICATIONSPapers ························································································································································
International Meetings ·······························································································································

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ACADEMIC DEGREES···························································································································

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COVER PHOTOGRAPHS·····················································································································

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102

EDITORIAR BOAD

ⅲ

The Organization ofLaboratory of Advanced Science and Technology for Industry
University of Hyogo
The organization
Director

Steering
Committee

Department ofLight and Particle Science and Technology

Department ofLight Aplication for Advanced Technology

Advanced Photon System
Beam Physics
Nanostructure Science and Technology
Guest Chair

Nanoscience and Technology utilizing
Synchrotron Radiation
Nano-Micro System
Bio-Medical Technology (to be established)
Guest Chair

Staff (FY 2011)
Research and faculty staff
MIYAMOTO Shuji, Professor, Director
KINOSHITA Hiroo, Professor
MATSUI Shinji, Professor
KANDA Kazuhiro, Professor
UTSUMI Yuichi, Professor
NIIBE Masahito, Associate Professor
SHOJI Yoshihiko, Associate Professor
WATANABE Takeo, Associate Professor
HARUYAMA Yuichi, Associate Professor
YAMAGUCHI Akinobu, Associate Professor
AMANO Sho, Research Associate
HASHIMOTO Satoshi, Research Associate
NODA Daiji, Research Associate
HARADA Tetsuo, Research Associate
OKADA Makoto, Research Associate

Administrative staff
MATSUMOTO Shigeki, General Manager
KOGA Hitomi, Manager
SONOHARA Kazuhiko, Chief
KAMIYA Miki, CAST
MAEDA Kaori, CASTYAMAMOTO Keiko, CASTYOKOYAMA Yuka, CAST
FUJIMAKI Hisae, CAST
KANATANI Naoko, NewSUBARUYAMADA Miki, CASTYAMAMOTO Mako, NewSUBARU
KUSUMOTO Kumi, CASTMORIGUCHI Miyuki, Harima Forum of
Science and Technology for 21st Century

Specially appointed staff
MOCHIZUKI Takayasu, Professor
MOTOYAMA Muneyuki, Professor

Open advanced research facilities initiative
staff
TERASAWA Mititaka, NewSUBARU
UMESAKI Masanori, NewSUBARUFUKUOKA Takao, NewSUBARUHORIKAWA Ken, NewSUBARUMIYAHARA Yoshikazu, NewSUBARUISHIKAWA Kazuko, NewSUBARU

Guest staff
OHOKUMA Haruo, Professor
ASANO Yoshihiro, Professor
TAKAHASHI Yukio, Associate Professor
NAGATA Yutaka, Associate Professor

Contact address
CAST (Center of Advanced Science and Technology, Hyogo)
3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1205 JAPAN.
T:+81-791-58-0249
F:+81-791-58-0242
NewSUBARU Synchrotron Radiation Facility
1-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1205 JAPAN.
T:+81-791-58-2503
F:+81-791-58-2504
Web URL http://www.lasti.u-hyogo.ac.jp/,
http://www.lasti.u-hyogo.ac.jp/NS/
e-Maillasti@lasti.u-hyogo.ac.jp
Accsess
http://www.lasti.u-hyogo.ac.jp/NS-en/access/ⅳ

Current Status of NewSUBARU

Beamlines
Takeo Watanabe and Hiroo Kinoshita
Center for EUVL, LASTI, University of Hyogo
Total nine beamlines are operating in the
NewSUBARU synchrotron facility. Four beamlines of
BL01, BL03, BL06 and BL11 were constructed until 1999.
Three beamlines of BL07, BL09 and BL10 were started theoperation from 2000.
BL03B beamline branched from the BL03 beamline
propose for the usage of the EUVL (extreme ultraviolet
lithography) microscope for the EUVL finished mask
inspection.
BL09B beamline branched from BL09 beamline for theusage of the usage of the EUV interference lithography toevaluate. And BL09C beamline branched from BL09B

beamline for the usage of the thickness measurement of the
carbon contamination originated to the resist outgassing
during the EUV exposure.
BL02 beamline was constructed for the usage of LIGA
in 2003.
BL05 beamline was constructed in response to ademand in the industrial world in 2008, that isenhancement of the analysis ability in the soft X-ray region
with the development of nanotechnology.
The arrangement of the beamlines in the NewSUBARU
synchrotron radiation facility is shown in Fig.1.

Fig. 1 Beamline arrangement in NewSUBARU.

I. BL01
BL01 is a beamline for research and developing newlight sources. This beamline is one of two long1straight section on NewSUBARU. Optical klystron
was installed at this straight section. Upstream side ofthis beamline (BL01B) is intended to be used forvisible and infrared light generated from FEL or SR.
Downstream side of this beamline (BL01A) is used
for laser Compton scattering gamma-rays source.
Gamma-ra y bea mline hutch j ust o utsid e o f thestorage ring tunnel was constructed in 2004 for
gamma-ray irradiation experiments. Specificationsof this gamma-ray source are listed in Table 1.

New gamma-ray irradiation hutch "GACKO" wasinstalled at BL01A, collaborating with Konan University.
Table 2 shows the specification of “GACKO”.
Table 2. Specification of “GACKO”
Maximum gamma-ray power
0.33 mW
Maximum gamma-ray energy
1.7MeV - 73 MeV
CO2 laser, wavelength/power
10.59µm/10W
1-1.7MeV gamma-ray flux
2×10^7
ȖVHF#:P$
Nd:YVO4 laser, wavelength/power 1.064µm/ 30W,
0.532µm/20W
10-17 MeV gamma-ray flux
5×10^7
ȖVHF#:P$

Table 1. Specification of BL01 gamma beamGamma energy : 1.7 - 4 MeV
CO2 laserȝP*DPPDIOX[ [ȖV
5W
[ȖV -1.7 MeV)ZLWKPPĳFROOLPDWRU
Nd laser
Gamma energy : 17 - 40 MeVȝP*DPPDIOX[ [ȖVȝP[ȖV -17 MeV)
5W
ZLWKPPĳFROOLPDWRU*Electron beam energy : 1-1.5 GeV*Electron beam current : 250 mA
gamma-ray beam divergence : 0.5 mrad

II. BL02
The LIGA (abbreviated name of Lithogaphic,
Galvanoformung and Abformung) process which consistsfrom deep x-ray lithography, electroforming, and molding
process is one of the promising candidates for such 3D
micofabrication. More than hundreds aspect ratio for
microstructure can be attained by the usa of the higher
energy x-rays (4-15 keV) from synchrotron radiation (SR)with deeper penetration depth to the photosensitive resist.
In this system we have succeeded to enlarged the exposurearea up to A4 size and the fabrication dimension from
submicron to millimeter by varying the energy of the x-ray
source in accordance with the size of desired microparts.
Micostructure with high aspect ratio over several hundreds
will bi achieved using the x-rays over 10 keV since highenergy x-ray has deep penetration depth to thephoto-sensitive resist materials. Whereas, in the case oflithography for low energy x-rays from 1 keV to 2 keV,submicron structures with high aspect ratio will beachieved using the x-rays mask with precise line-width andthinner absorber, since low energy x-rays has low
penetration depth. Based on this principle, the beamilne for
x-ray exposure have constructed with continuous
selectivity of x-rays frpm 100 eV to 15 keV by using the

x-ray mirrors (plane and cylindrical mirror) and Be film
filters. The horizontal angle of the outgoing SR could beobtained up to 12.5 mrad, which corresponds to thehorizontal size of 220 mm (A4 horizontal size) at the
exposure position. The second characteristic performanceof the beamline is the high efficiency differential pumping
system. This was necessary for maintain the vacuum
difference between the storage ring (<10-9 Pa) and theend-station (<10-9 Pa) at which gasses for substrate coolingwill be introduced in the exposure apparatus.
The flexibility for the shapes and functions of
microstructure will be enlarged by achieving 3D
microfabrication process using multi step exposure atvarious configuration between x-ray mask and substrates.
The relative positions between x-ray mask and substrates,
tilt and rotation angle to the SR incident direction can be
moved simultaneously during SR exposure using 5 axis
stages. The movement of each axis is controlled by the PC
in terms of the scanning speeds, scanning length, andrepetition number. In order to decrease the heat load ofsample substrate suffered during SR irradiation helium
introduction and substrate cooling mechanism were alse
equipped. Specification of spectrometer is listed in Table 3.

2

Table 3. Specification of the LIGA exposure system
OpticsPlane and cylindrical mirror, Be filters
Exposure energy
100 - 2 keV, and 4 – 15 keV
Exposure method
Proximity and multi step exposure
Wafer size
A4 or 8 inch
Exposure area
230 mm(H) 300 mm(V)
Exposure environment< 1 atm (He-gas)

III. BL03
BL03 is a beamline for the developing the next
generation lithographic technology so called extreme
ultraviolet lithography (EUVL). The exposure tool isinstalled at the end station. Using this exposure tool, theresearch and development of the next generation
lithography such as the less than 70 nm node is going on
process. The exposure wavelength is 13.5 nm.
The semiconductor industry plays a very important rolein the information technology (IT). In 2006, 256 Gbit
DRAM with a gate length of 70 nm will be demanded in
the IT industry. The extreme ultraviolet lithography(EUVL) is a promise technology for fabricating a finepattern less than 70 nm. To meet this schedule, thistechnology has to be developed in the pilot line until 2004.
As for the practical use, it is very important that both toachieve large exposure area and to fabricate fine patterns.
Therefore, at Himeji Institute of Technology, large
exposure field EUV camera consists of three asphericalmirrors was developed. First in the world, we fabricated 60
nm line and space pattern in the large exposure area of 10
mm×10 mm on a wafer. Furthermore, BL03B beamline
branches from the BL03 beamline propose for the usage of
the EUVL microscope for the EUVL finished mask
inspection. Table 4 shows the specification of ETS-1.

Table 4. Spectification of the exposure tool (ETS-1)
Imaging optics
Three aspherical mirrors
Exposure wavelength13.5 nm
Numerical aperture
0.1
Demagnification
1/5
Resolution
60 nm
Depth of focus
0.9 µmExposure area (static)
30 mm1 mm
Exposure area (scanning)
30 mm28 mm
Mask size
4 inch, 8 inch, and ULE 6025
Wafer size
8 inchExposure environment
In vacuum

IV. BL05
BL05 was constructed in response to a demand in theindustrial world, that is enhancement of the analysis ability
in the soft x-ray region with the development of
nanotechnology. BL05 consists of two branch lines for use
in the wide range from 50 eV to 4000 eV. BL05A and
BL05B are designed to cover the energy range of
1300-4000 eV and 50-1300 eV, respectively. The incident
beam from the bending magnet is provided for two branchlines through different windows of a mask. Therefore,
these two branch lines can be employed simultaneously.

1) The double crystal monochromator was installed at
the BL05A. InSb crystals and Si crystals are prepared for a
double-crystal monochromator. Toroidal mirrors are used
as a pre-mirror and a focusing mirror of BL05A. XAFS
measurement in the total electron yield mode andfluorescence XAFS measurement using SSD (SII Vortex)
can be performed. The fluorescence XAFS spectra can bemeasured for samples at the end station filled with He gas.
Table 5 shows the specification of monochromater.

3

Table 5. Monochromator specification
Monochromator
Double crystal monochromator
Monochromator crystals
InSb(111), Si(111)Energy range
1300-4000 eV
E/㼺E=3000
Resolution

2) The constant-deviation monochromator consisting of ademagnifying spherical mirror and a varied-line-spacing
plane grating (VLSPG), which can provide high resolution,
simple wavelength scanning with fixed slits, was mounted
on BL05B. The optical system consists of a first mirror(M0), a second mirror (M1), an entrance slit (S1), a
pre-mirror (M2), and three kinds of plane grating (G), an
exit slit (S2) and a focusing mirror (M3). The including
angle of the monochromator is 175°. Two measurement

Monochromator
Grating
Energy range
Resolution

chambers are prepared at the end station of BL05B. The
XAFS spectra in the total electron yield mode andfluorescence XAFS spectra using SDD (EDAX) can bemeasured in a high vacuum chamber. In addition, thephotoelectron spectrum can be measured using sphericalelectron analyzer (VG Sienta, R3000) in an ultra
high-vacuum chamber. The chambers can be replaced byeach other within 1 hour. Table 6 shows the specification of
the monochromator.

Table 6. Monochromator specification
Varied-line-spacing plane grating monochromator
100 l/mm, 300 l/mm, 800 mm/l
50-1300 eV
E/㼺E=3000

V. BL06
BL06 has been mainly developed for irradiation
experiments such as photochemical reaction, SR-CVD,
photo-etching, surface modification. The white radiation
beam from bending magnet is introduced to the sample
stage using a pair of mirror, whose incident angle was 3q.
The SR at BL06 sample stage had a continuous spectrum
from IR to soft x-ray, which was lower than 1 keV. A

differential pumping system can be utilized forexperiments in a gas atmosphere, which is difficult in thesoft x-ray region. A sample holder can install four pieces ofsamples at a time. By using heater set in the sample holder,
the sample can be heated from room temperature to 220qC.
The temperature of sample is monitored using a Cr-Al
thermocouple mounted on the sample holder.

VI. BL07A and BL07B
This beamline was designed for the development of
new materials by SR technology. This beamline consists of
two branch lines, which are provided with an incident
beam from a 3-m undulator by switching the first mirror.
One of them is a high photon-flux beamline with amultilayered-mirror monochromator for the study of
SR-process (BL07A) and another is a high-resolution
beamline with a varied line spacing grating
monochromator for the evaluation of nano-structure
characteristics by SR-spectroscopy (BL07B). The usefulrange of emitted photons from 50 to 800 eV is covered atboth beamlines. The light source of BL07 is a 3-m lengthplanar undulator, which consists of 29 sets of permanent
magnets, a period length of which is 76 mm. The incident
beam from the undulator is provided for two branch lines
by translational switching of first mirror.

1) BL07A
The multilayered-mirror (MLM) monochromator,
which has high reflectivity in the soft X-ray region, wasinstalled at the BL07A. It consists of a switching mirror
chamber, a slit chamber, a MLM monochromator, a filter
chamber and a reaction chamber. To obtain a large photon
flux, we decided to use only first mirror (switching mirror),M0, for focusing. The MLM monochromator is designed tocover an energy range of up to about 800 eV by
combination of three kinds of mirror pairs with 4 kinds offilter. The flux deliver by this design is estimated to be
between a maximum of 1017 photons/s at 95 eV and aminimum 2u1014 photons/s at 300 eV for a 500 mA ring
current. Table 7 shows the summary of BL07A.

4

Energyrange(eV)

Material

50-60
60-95

Mo/Si

90-140140-194
190-400
400-560

Mo/B4C
Ni/C

Table 7. Summary of BL07A.
Multilayer mirror
spacing
Thickness number of
Ratio
layers
20 nm
11 nm
5 nm

0.8

20

0.5

25

0.5

60

'E/E
6.2 %

None



Ag

100 nmCr

500 nmNi

500 nm

3.3 %
2.5 %

550-800
2) BL07B
The constant-deviation monochromator consisting of ademagnifying spherical mirror and varied line spacing
plane grating (VLSPG), which can provide to highresolution, simple wavelength scanning with fixed slits,
was mounted on BL07B. The optical system consists of afirst mirror (M0), a entrance slit (S1), a premirror (M1),and three kinds of plane grating (G), an exit slit (S2) and afocusing mirror (M2). The monochromator is designed toFiltermaterial
Thickness
Al
100 nmcover the energy range 50-800 eV with three gratings, ofwhich including angle are 168q. The VLSPG has been wellknown to obtain high resolution in extreme ultraviolet
region by diminishing various kinds of aberration. The
total resolving power about 3000 can be realized in thewhole energy region. Table 8 shows the specification of themonochromator.

Table 8. Monocromator specification
Mount type
Hettrick-Underwood type
Grating G1, G2, G3
Plane VLS (600 l/mm, 1200 l/mm, 2400 l/mm)
Energy range
50-150 eV, 150 – 300 eV, 300-800 eVResolving power (E/ǍE)㨪3000

VII. BL9A purpose of this beamline is studies on a soft x-ray
interferometry or a holographic exposure experiment withmaking use of highly brilliant and coherent photon beams
radiated from 11 m long undulator in NewSUBARU.
BL09 consists of M0 mirror, M1 mirror, G grating andM2 and M3 mirror. M0 and M3 mirrors are used forhorizontal deflection and beam convergence, M1 is usedfor vertical beam convergence at the exit slit, and M2 isused for vertical deflection and beam convergence. A
monochromator is constructed by M1 and a plane grating.
The maximum acceptance of the undulator beam is 0.64
mrad in horizontal and 0.27 mrad in vertical. The

acceptance can be restricted by 4-jaw slits equipped at
upstream of the M0 mirror.
BL09B beamline branched from BL09 beamline for theusage of the EUV interference lithography for theevaluation of the exposure characteristics of EUV resist.
Coherence length of 1 mm at the resist exposure position
was achieved using BL09B beamilne. And BL09C
beamline branched from BL09B beamline for the usage ofthe thickness measurement of the carbon contamination
originated to the resist outgassing during the EUV
exposure. Table 9 shows the specification of themonochromator.

Table 9. Monochromator specification
Mount type
Hettrick-Underwood type
Grating
Plane VLS (900 l/mm)
Energy range
50 – 600 eVResolving power (E/ǍE)
㨪3000

5

VIII. BL10
BL10 is for the global use in the Himeji Institute ofTechnology. M0 mirror is used for horizontal deflection andbeam convergence, M1 is used for vertical beam
convergence at the exit slit, and M2 is used for verticaldeflection and beam convergence. A monochromator isconstructed by M1 and a plane grating. At the beginning,the multiplayers reflectiveity measurement was carried out
at this beamline. The characteristics of this beamline andthe result of the Mo/Si multiplayers measurement are
carried out for the development of the EUVL mask
techmology.
BL10 utilizes a monochromator of the varied line
spacing plane grating monochromator (VLS-PGM). Theline density of the monochromator in central region of thegrating is 600 lines/mm. The reflectometer is a two axis
vacuum goniometer using two Huber goniometers. One

axis carries the sample, which may for examplee be amirror at the center of the reflectometer vacuum tank(T-motion). The other (M-motion) carries the detector on arotating arm. In addition there are through-cacuum linear
motions to translate the sample in two orthogonal directions(x,y). All motors are controlled by computer. The sample
itself is mounted on a kinematic holder. The controlstage
monochromator rotation, and data analysis were programusing LABVIEW software. The reflectivity result obtainedat BL10 has a good agreement with that at LBNL.
 The mirso-CSM tool was adapted at the mostdownstream of the BL10 beamline fot the EUV mask defectinspection. This too is very effective for the inspection of
the actinic patterned mask. Table 10 shows the specification
the monochromator.

Table 10. Monochromator specification
Mount type
Hettrick-Underwood type
Grating
Plane VLS (600 l/mm)
Energy range
50 – 600 eVResolving power (E/ǍE)㨪1000

IX. BL11
A beam line BL11 is constructed for exposure Hard
X-ray Lithography (DXL) in the LIGA (German acronym
for Lithographite Galvanoformung and Abformung)process. LIGA process, that utilizes a useful industrial
application of SR, is one of the promising technologies forfabrication of extremely tall three-dimensional
microstructures with a large aspect ratio. This process wasinvented at the Institut Fur Mikrostrukturtechnik (IMT) of
the Karlstuhe Nuclear Center (KfK) in 1980.
Microstructures with height of over a few hundreds µm
have been widely applied to various fields such as
micro-mechanics, micro-optics, sensor and actuator
technology, chemical, medical and biological engineering,and so on. This beam line was designed by the criteria ;photon energy range 4 keV to 6 keV, a beam spot size on
the exposure stage t 50u5 mm2, a density of total
irradiated photons t 1011 photons/cm2. BL11 of anabsorber chamber, a first-mirror chamber (M1), a
second-mirror chamber (M2), a 4-way slit chamber, a Be
window chamber, and an exposure chamber. The second
pre-mirror is bent elliptically using a bending mechanism.

Fine bending adjustment of the M2 mirror can be made in
the UHV by the pulse motor. The LIGA process needs thephoton energies of 3 keV to 6 keV, the optics of a LIGA
beam line generally employ a Pt monolayered-mirror anda Be window, which cuts off low-energy photons. The
reflectivity of a Pt-coated mirror is about 55 % in therange of photon energy from 2 keV to 4 keV, however, it
drops to 30 % at the photon energy of 6 keV. Therefore,
new materials with a high reflectivity must to be found for
Deep X-ray lithography (DXL) in this energy range. We
propose the use of a Ni/W/C multilayered-mirror with agraded d-spacing in the range of photon energy from 3 eV
to 6 keV. The calculated reflectivity of the Ni/W/C
multilayered-mirror is higher than 56 % at the photon
energy of 6 keV with a glazing incident angle of 0.8
degrees, and photons that have higher photon energy than
6 keV can be removed A 200 µm-thick beryllium (Be)window in a Be window chamber is used to separate theultra-high vacuum part from the low vacuum part and to
cut off low-energy photons. Table 11 shows the
specification of the LIGA exposure system.

6

Table 11. Specification of the LIGA exposure system
Exposure method
Proximity exposure
Wafer size
4 inch50mm(H)80mm(V)Exposure area
Exposure environment< 1atm (He-gas)

7

NewSUBARU Storage Ring
Y. Shoji
The total machine time in FY2011 was 2661 hrs,
115% of that of FY2011, including the beam downtime. Fig. 1 shows the breakdown. The beam downtime includes not only the down by a failure, butalso off-beam periods by a beam abort or others dueto the beam instability. The category 'beam line
commissioning' had been included in the user time
until FY2011. The total of the normal user time andthe beam line commissioning in this FY, 1850 hrs,
was about 121% of that in FY2011. Time formachine study and special users was 128% of that in
FY2011. The down time due to the machine trouble
was 1.0%, the same level with that in FY 2011.

Storage Ring Parameters
The machine parameters of the 1.5 GeV storage
ring are listed in Table I. Although the machinecondition remains the same, some of the values arerevised according to the new model calculation.
Table I Main parameters of the NewSUBARU
storage ring in FY2011.
Circumference
118.73 m
Bending lattice typemodified DBA
Number of bending cells 6
Straight sections
4m X 4, 15m X 2
Bending radius
3.22 mInjection energy
1.0 GeV
Maximum energy
1.5 GeV
RF frequency
499.955 MHz
Betatron tune
6.29 (H), 2.23 (V)Momentum compaction factor
0.0014
Electron energy
1.0 GeV 1.5 GeV
RF voltage
100 kV 260 kV
Natural energy spread
0.047% 0.072 %Natural emittance
50 nm 112 nm
Maximum beam current 500 mA

Machine Troubles
The machine troubles in FY2012 are listed inTable II. The rate of hardware troubles wasincreasing. We had troubles in two different timing
modules. The synthesizer, which is used as a
500MHz master signal generator, had a trouble in
AC-DC units and the signal became noisy. This was
not counted in down time because we could continueuser operation. We had troubles in 5 magnet power
supplies.
Machine Study and Special User Time
Table III shows the list of machine studies in
FY 2012. One special theme, a research related toa production of Laser-Compton backscattering γray and its use, took more than 50% of themachine study time. Most of them took place
after the completion of the new γ-ray hatch at
BL1 in November 2012.
Most of the study reports are open to the public
on the home page of NewSUBARU ( http://www.
lasti. u-hyogo. ac. jp/ beam_physics/ NewSUBARU).

Operation Status
The ring has two user-time operation modes, 1.0
GeV top-up operation mode and 1.5 GeV operation
mode. The basic operation time is 9:00 - 21:00 of
weekdays. Monday is used for machine R&D,
Tuesday is for 1.5 GeV user time, Wednesday andThursday are for 1.0 GeV top-up user time, Friday isfor 1.0 GeV or 1.5 GeV user time. Night period orweekend is used for machine study and user timewith the special mode, single bunch operation andLaser-Compton Gamma ray, if necessary.

Accelerator Improvements
The top-up operation current has been raised
from 250 mA to 300 mA since October 2012. Fig.2
shows typical operation in these 5 years. This
improvement was achieved by longer lifetime as aresult of an additional installation and optimizationof sextupole magnet families. The harmonic
sextupole family named 'S1' was separated to 'S1','S3OK', and 'S3LU' and they were connected to the
independent power supplies.
New vertical kicker magnet system was installed
at one of the long straight sections. Its pulse shape
was 450 ns width half sine, a little bit longer than therevolution period. The main purpose of theinstallation was the accelerator physics research togenerate narrow band coherent THz radiation.
However it is useful also for various researches andmachine parameter measurements.

beam down time by machine troubles
27 hrs (1%)
machine tuning
239 hrs (10%)

machine study &special user time
545 hrs (20%)

normal user time
1191 hrs(44%)
beamline
commissioning
659 hrs (25%)

Figure 1: Machine time in FY2012.

8

stored beam current (mA)

350
300
250
200

Oct. 2012; 300mA
Nov. 2011; 250mA
Oct. 2009; 220mA
Sep. 2007; 200mA

150
100
50
0

1GeV top-up
operation
9:00 11:00 13:00 15:00 17:00

time

Figure 3: Newly installed vertical kicker system.
.

Figure 2: Improvement of top-up operation current
in these 5 years.

Table II

Machine troubles in FY2012.

Group
Operation
Operation

Failure/trouble
beam down time (hr)Miss operation (human error)
0.9
Beam loss by a beam instabilities
3.6
Schedule delay by SPring-8 trouble
2.3
RF & Timing
Timing module
11.3
Synthesizer (noisy signal)
0.0
MagnetPower supply
3.7
Beam monitor line Cooling water leak at SR5
5.2
Utility
Electric power down by a thunder
0.4

Table III

List of machine studies in FY2012. The unit of study time is counted by shifts (typically 12 hrs).

R＆D theme and special user mode
Laser-Compton backscattering γ-rays
Parameter tuning for various energy operations
Commissioning of visible light profile monitor port SR5
Skew quadrupole coupling correction
Coherent synchrotron oscillation feed-back
Betatron amplitude dependent orbit shift
Coherent synchrotron radiation by chromaticity modulation
Linear lattice model confirmation
Commissioning of the multi-element corrector
Identification of RF noise source (synthesizer trouble)

9

responsible person
S. Miyamoto
S. Miyamoto
Y. Shoji
Y. Shoji
Y. Shoji
Y. Shoji
Y. Shoji
Y. Shoji
Y. Shoji
Y. Shojistudy shift
33
1
5
6
1
1
9
1
6
2

10

Research Activities

Tentative Design Parameters of 1.5 GeV Injector
Synchrotron for New SUBARU
Y. Miyahara
New SUBARU, LASTI
Abatract
So far, an electron beam has been injected in the New SUBARU storage ring from the SPring-8 injector
linac at 1.0 GeV, but this system is not necessarily permanent. To prepare for an unexpected situation, 1.5 GeV
injector synchrotron for the storage ring was considered. Design parameters of the synchrotron and the beamtransport from the synchrotron to the storage ring are presented. An improved performance is expected by the
top-up injection at the higher energy.
1. Comparison of injection parameters
Injector
Injection energy
Energy spread
Emittance
Inj. beam size
Pulse Current
ChargeInitial inj. period.
Top up inj periodStored current
Inj. timeEin(GeV)
E/Ein(%)
xin (rad m )x(mm)
I(mA)
Q(nC)
in(s)
tp(s)
I0(mA)
t(min)SP-8 linac
1.0
1.0
100*10-9
1.0
0.5
0.2
1.0
30
250
10

NS synch
1.5
0.06
208*10-9
1.4
0.5
0.2
1.0
30
250
10

NS-linac0.05
1.0
1*10-6
5
2.5
1.0
1.0
30
10

2. NS Synchrotron1) Lattice
1.5, 0.05
Beam energy
E０ Einj (GeV)
Circumference
C (m)59.3644
Symmetry
Ns
Average radius
R (m)9.44830.0683
Momentum comp. fac. p
6.0x10
Energy spreadE/E0
3.25, 2.15
Tune
Qx, Qy3.35, 4.14
Natural chromaticity
x, y208
Emittancex(nmrad)Twiss param xmax,ymax, xmax (m)8.03, 15.39, 2.08
Bend mag (rect angular)
Field
B (T)
1.1, (0.0366)
2.3815
LengthlB (m)
12
Number NB
Quad mag
2.5243, -2.3465
Field strength
KF, KD, (m )0.35, 0.3
LengthlF, lD
12x2
NumberNQ
Operation
1
RepetitionfR (Hz)Single bunch
Extraction
Length(m)Field(T)Angle(deg)
0.4
0.02
0.26
Kicker
Kex
Bump
Bu
0.2
0.04
0.26
SeptumSP3(pulse)
0.3
0.4
1.37
SP4(DC)
1.2
1.2
15.1

11

On-axis Injection
SeptumKicker

0.4
0.2

SPin
Kin

2) RF system
Revolution freq.
RF freq
Harmonic num.
RF voltage
RF bucket height
Synchrotran tune
Bunch lengthf0 (MHz)fRF (MHz)h
VRF (MV)ERF/E0
Qs (ps)3) Vacuum
Pressure (in beam)
Below chamber
Pump station

P (Torr)
H*V (mm2)NP

10
108x3412

Npm
fast, slow

121+14) Monitor
Position
Beam current
Tune monitor
3.

5.05
500
99
4 (0.2)0.016 (0.019)
0.054
0.24

Injector linac

Beam energy
RF freq
Energy spread
Rep
Pulse length
Pulse electron
Emittance

4. Beam Transport
New
Bend
NB
B (T)
lB (m)Quad
NQ
lQ (m)

Einj (MeV)
fRF (MHz)E/E (%)
fr (Hz)lp (ns)nex(rad m)

50
2856+/- 1.0
1
1
1010
106

3
1.1
1.349, 2.382
11
0.25, 0.3, 0.35

Old ( necessary to check PS and Mag)
1 (necessary to reconstruct)
Bend
NB
B (T)
0.933 (assumed,)
1.215 (assumed)lB (m)
10
Quad
NQ
0.25, 0.3, 0.35
lQ (m)
Beam position monitor
Steering mag
Vacuum pump

12

Fig.1.

Layout of 1.5 GeV injector synchrotron

Fig.3.

Fig.2. Lattice functions of synchrotron

Beam transport from synchrotron to storage ring

13

(a)

First straight section around B0 to B1(c)(b) 2nd straight section around B1 to B2

3rd straight section around B2 to B3
Fig.4.

Lattice functions in the beam transport line

14

Calibration of Pyrgeometer by Blackbody
Radiation with RMS method on New SteadyState Equation of Heat Transfer
aY. Miyaharaa and T. Aoshimab) New SUBARU, LASTI, miyahara@lasti.u-hyogo.ac.jp,b) EKO instruments

Abstract
Calibration of pyrgeometer was performed using blackbody radiation, for which a new
steady state equation of heat transfer in the pyrgeometer was developed. Expansion
coefficients in the equation were determined by rms method on the experimental data,
which, however, depend much on the undefined constant α of thermopile voltage used fortemperature measurement in the pyrgeometer. The coefficients were also determined using
numerical values of physical properties of its components. It was demonstrated for the firsttime that both coefficients well agree at a special value of α.
1.

Introduction
Pyrgeometers, PIR of Eppley Laboratory Inc.
and MS-200 of EKO Instruments for example, arewidely used to measure infrared radiations, whichcoming down from the atmosphere around the earth.
It is composed of silicon dome, sensor plate andcontainer (body). The dome coated with
anti-reflection layer, passes infrared but not visible
wave. The sensor is connected to the body with heat
conductor. Its calibration is performed by injecting aslowly varying blackbody radiation from a conicalcavity, when temperatures of the cavity, dome andbody (TB, Td, Tb) are precisely measured. A
thermopile is used to measure voltage V due totemperature difference between sensor and body.
Calibration of PIR was originally performed ona steady state equation of heat transfer in considering
dome effect [1], after which several investigations
were reported. Typical example is as follows [2.3].
Measured data of X = σ(Ts4 – Td4) and Y =σ(TB44– Ts ) are plotted on (X, Y) plane, and fitted with astraight line. Then, coefficients a and k in thefollowing equation are determined as a = 246.3
W/m2/mV and k = 3.16 with errors of ∆a = 10.3 and∆k =0.03,

FIG. 1. Schematic diagram of heat transfer inpyrgeometer. Multiple reflections of radiation
between sensor and body are not drawn. Symbols are
explained in text.
much different from the experimental value. For along time, however, little attention has been paid tothe disagreement, which can be solved by improving
the steady state equation, as discussed below.
Above investigations are all based on the same
assumption of heat transfer of radiations above thesensor and the one through the conductor. In thepresent study, we additionally consider three factors;
1) heat transfer between the sensor and body byradiations, 2) heat transfer from sensor to the air or
gas in the body by convection, 3) form factor Γd =2.094 of semi-spherical dome for radiation
convergence on the sensor (see Fig.1). Note thatmultiple reflections between sensor and body are notdrawn in the figure to avoid complexity, and no
multiple reflections between sensor and dome are

σ (TB4 − Ts4 ) / V =a + kσ (Ts4 − Td4 ) / V(1)
where σ is the Stefan-Boltzmann constant and
suffixes B, s and d stand for the cavity, sensor anddome, respectively. Practically, Tb is used in place ofTs since Tb is very close to Ts. The coefficients a andk are expressed as a = a’(1− ρdρs)/(τdεs) and k = εd/τd,where a’ is transfer coefficient of thermopile, ρ thereflectance, τ the transmittance, and ε the absorption
coefficient.
Efforts have been made to improve the accuracy
using more detailed equations [4~6]. In all cases,
however, physically-expected values of a, k andothers in the equations are not given explicitly. If weapply probable values εd = 0.05 and τd = 0.7 in Eq.(1),for instance, we obtain k = 0.071, which is15

considered because of black surface of sensor upside.
Then, the steady state equation can be expressedassensor and that of the cross section of conductor with
R = Ac/As.
Eq.(2) can be simplified asτ d QB + ε d Γ d Qd + ε s ρ d Qs + FbQb + Fs 2Qs= (Qs +

Qh

εs

)+

1− R

εs

(ε s 2Qs + Qh ) +Rεsδ Q ≡ QB + aV + sQs + bQb + dQd + hQh =
0

Qc

(3)
where a, s, b, d and h are expansion coefficients.
Comparing Eqs.(2) and (3), we obtain(2)

where symbols Fb and Fs2, are given by

ε s2
ε b (1 + ρb ρ s 2 + ρb2 ρ s22 )(1 − R)εsεFs 2 ≡ s 2 ε s 2 ρb (1 + ρb ρ s 2 + ρb2 ρ s22 )(1 − R)εsa* = −

Fb ≡

b* =

j

sj

2
sj

εs

Fb

εd
*
d=
Γ
τd d

τd

τd

h* = −∑V Q ∑V Q ∑V Q   a   −∑V Q 
∑ Q Q ∑ Q Q ∑ Q Q   s   −∑ Q Q ∑ Q ∑ Q Q ∑ Q Q   b  =  −∑ Q Q 
∑ Q ∑ Q Q   d   −∑ Q Q ∑ Q   h  −∑ Q Q 
j

bj

j

dj

j

hj

j

Bj

bj

sj

dj

sj

hj

sj

Bj

dj

bj

hj

bj

Bj

hj

dj

Bj

hj

Bj

sj

2
bj

mij = m ji

τd

bj

τd

(2 − R)(4b)

ε sτ d(4c)
The coefficients are marked with (*) to represent
them as physically-expected values. Note that b* andd* are both positive, which becomes important later.
Experimentally, TB, Tb, Td and V are measured at
tj with j = 1~960, from which we can obtain optimum
values of the expansion coefficients by applying rms
method to Eq.(3). The coefficients are given by thesolution of the following equation;transfer coefficient of Hg ≈ 5 W/m2/K in no-streamgas. Suffix s2 indicates the downside of the sensor.
The voltage of thermopile is given by V = α(Ts-Tb)
with α proportional constant. As and Ac are the area of

∑V Q
∑Q

(4a)

F
ε
ερ
1
− [1 + s 2 (1 − R )] + s d + s 2
s* =The left and right hand sides of Eq.(2) are theentering and go-out of heat with respect to the sensor,
respectively. Qx (x= B, s, b, d) = σTx4 is the radiationenergy, and Qc = (λ/L)(V/α) is the heat transfer
though the conductor with λ the heat conductivity
and L the length, The heat transfer to the gas is givenby=
Qh H g (Ts − Tg ) , where Hg is the heat ∑ V j2








1 R λ
α ε sτ d L

2
dj

dj

2
hj

(5)

At the same time, the voltage V = α∆T is measured
with a thermopile, which is composed of a series of70~100 copper-constantan thermo-couples with atemperature coefficient of 0.043 mV/K each. Thus,
the proportional constant is α = 3.0~4.3 mV/K. Timevariation of measured temperatures is shown in Fig.
2.

where the matrix is symmetric with mij = mji.
The expected and optimum values ultimately should
agree with each other. However, the agreement isreduced as the decrease of the completeness of steadystate equation and experimental data.

2.Experiment and analysis
Experiments were performed with MS-200 in
the same way as [2.3]. It is placed upside down, andthe dome is covered with the cavity. Alcohol anddry-ice are mixed to provide a low temperature liquid,
which is circulated through a double-wall bath in thecavity. The liquid temperature, controlled by electricheater, is measured at several points to provide theiraverage temperature TB. Nitrogen gas is softly brew
upon the dome to change its temperature somewhat
independently. The temperatures of inner surface ofdome and body are measured with platinum
resistances. The infrared radiation at the earth surface
is about 270 W.m2, which corresponds to about -11 ℃.

In performing numerical calculation with Eq.(5),
we take into account three undefined factors. The
constant α of V = α ∆T is not yet determined, andthere is alternative possibilities of ∆T = Ts – Tb and∆T = Tb – Ts since the connection is not quite sure. In
addition, the gas temperature Tg is not measured.
Accordingly, first we assume Tg = (Ts + Tb + Td)/3,
and scan α for two possibilities of ∆T.

16

Table 1 α dependence of expansion coefficients for V = α(Tb– Ts)===============================================================================
α
Tg(n)
CASE
a
s
b
d
h
<dQ>rms
KA208-238.09-2.0700.447
0.630-7.957
0.367
3.4
Tg(1)
KA217
-240.30-1.556
0.417
0.145-10.484
0.403
4.0
Tg(1)
KA218
-250.91
1.5390.421
0.124-44.696
0.442
4.0
Tg(2)
KA219
236.061.5480.420
0.135-7.808
0.341
4.0
Tg(3)
KA223
272.77-2.901
1.066
0.841
-17.053
0.668
4.2
Tg(1)
KB 302-213.23-1.5860.430
0.163-3.1060.419
3.96 Tg(1)-------------------------------------------------------------------------------------------------------------------------------------a*
s*
b*
d*
h*
-------------------------------------------------------------------------------------------------------------------------------------Ex 22-213.74
-1.5490.466
0.149-2.850
Note :
Tg(1) = (Ts+Tb+Td)/3, Tg(2) = (8Ts+Tb+Td)/10,Tg(3) = (2Ts+4Tb+4Td)/10, Tg(4) =(5Ts+2.5Tb+2.5Td)/10
Ex 22 in the bottom of the table. We see that total
tendencies of the optimum and expected values wellagree each other. Especially, all coefficients in thecase of α = 4.0 agree very well, while d and d* areconsiderably different in the cases of α = 3.4 and 4.2.
Among three cases KA217, 218 and 219 of α =4.0 in the table, we see that coefficient h varies
substantially depending on Tg(n), but othercoefficients not so much. Thus, h dependence on (α,Tg(n)) was surveyed as shown in Fig.3. The open andclosed circles in the figure represent the cases where
both b and d are positive and negative, respectively,
and broken line represents the region of abs(h) < 6.
Consequently, the most optimum values are obtainedat α = 3.96 and Tg(1) = (Ts + Tb + Td)/10 with h =-3.1 compared with h* = -2.8.
Finally, we discuss the physically-expectedvalues. The silicon dome is coated for ant-reflectionof infrared wave. Body and sensor are made ofanodized aluminum. Upper surface of sensor isFIG. 2. Time variation of measured temperatures,
painted black. However, physical parameters (sizeTb, Td, and TB as well as thermopile voltage V.
and optical properties) of these components are notpublished. Then, we assume the following
parameters;
First, we consider the case of V = α(Ts-Tb). The
α= 3.96, Γd = 2.094, λ = 273 W/m/K,
coefficients were calculated with Eq.(5) in the
L = 0.002 m, R = 0.005, εs = 1.0
cases α = 2.8~4.2 at a step of 0.1. In all cases the rms
τ2
d = 0.7, ρd = 0.25, εd = 0.05
errors are as small as <δQ>rms = 0.3~0.8 W/m .
ε
b = εs2 = ρb = ρs2 = 0.5
However, these cases are all physically inadequate.
The
expected values, which calculated withAs shown in Eqs.(4c), b* and d* are both positive, sotheseparameters,
are given by Ex 22 in Table 1. The
that b and d are expected to be positive, but there aretransmittanceofsilicon crystal in infrared region,
no such cases in the above calculations.
generallyabout
0.5, increases with the aid of
Second, we consider the opposite case of V =anti-reflection
coating,
to about τd = 0.7. It is known
α(Tb-Ts) The coefficients were calculated in the casethatabsorption
intheregionis very small, so that εd =of α = 2.8~5.0. In these cases, the errors are also
0.05
isassumed.
Anodizedaluminum,
covered withvery small, and b and d are negative in almost all
porousoxide
withathicknessof
10~200µm,
cases. However, we find both b and d are positive inbecomes
glossybymachining,which
approximately
the cases, KA208 (α = 3.4), KA209~211 (α = 4.0)
provides ε = ρ = 0.5. Parameter R is determined so as
and KA223 (α = 4.2), as shown in Table 1.
tomake a* close to a, since a* depends much on R.
Physically-expected values, which calculated
BecauseR << 1, then h* is automatically close to hwith physical parameters given later, are shown by17

Table 2
Comparison of each term xQx in KB 302 (α = 3.96) at tj = 500.
===============================================================================
Term
B
a
s
b
d
h
δQ
Tx(K)
274.23296.74296.59295.61296.31
320.68-0.580439.63438.77433.002.15
Qx(W/m2)x
1.000-213.23
-1.5860.430
0.163-3.106xQx (W/m2)
320.68123.67-697.25
188.67
B70.58-6.58-0.23Note） Th = Tg = (Ts + Tb + Td )/3；Qh = 5(Ts – Tg) ；Qa =V(mV)(= -3.1). The small value of R is probable if we
imagine narrow bridges between the sensor and body.
The form factor Γd = 2.094, numerically calculated inreference to Fig.4, makes the agreement better. If we
set Γd = 1.0, we have d* = 0.075, being muchdifferent from d = 0.163. For comparison, we apply
the rms method to Eq.(1) with Tb in place of Ts on thepresent data, then we have a = 255.10 and k = 5.164(while 0.071 expected) with <δQ>rms = 1. 46.
Table 2 compares the magnitude of all terms at tj= 500 in the case of KB302 (α = 3.96). We see thatthe contribution of sQs in the total (= δQ) is
especially large, which is because radiation is emitted
from both sides of sensor. The contribution of hQh issmall, but not negligible compared with the error δQ.
The temperature difference of Ts – Tb = 0.15 K and
Ts – Tg = 0.43 K are small, but neither negligible todetermine the optimum values.

values of the coefficients were also determined byrms method on the experimental data. It was foundthat expected and optimum values agree very well ata special value of α with a very small error <δQ>rms.
Further details and applications are discussed on thebasis of the new steady state equation.

FIG.4 Form factor Γd = Q0sn/Q0, the ratio ofradiations on the sensor and dome, is calculated inreference to this figure. Details are given elsewhere.

References[1] B. Albrecht and S.K.Cox, J. Appl. Meteor.,
16, 188 (1977).
[2] G. BrogniezJ. C. Buriez, J. C. Vanhoote,and Y. Fouqualt, Beitr. Phys. Atmosph. 59, 538(1986).
[3] M. Shiobara and S. Asano, J. Aerol. Obs.
43, 17 (1992).
[4] R. Philipona C. Flohlich and C. Betz,
Appl. Opt. 34, 1598 (1995).
[5] R. E. Payne and S. P. Anderson, Ame.
Meteoro. Soc., 16, 739 (1999).
[6] Y. Hirose and S. Shibata, J. Aerol. Obs.60,
25 (2000), 61, 43 (2001), 62, 67 (2002).

FIG. 3, Optimum values of expansion coefficient hon (α, Tg(n)) plane.
In conclusion, a new steady state equation onheat transfer in pyrgeometer was developed byintroducing three factors; 1) heat transfers between
sensor and body, 2) heat transfer from sensor to thegas in body, 3) form factor for the convergence ofdome radiation. Expected values of expansion
coefficients of the equation were calculated using
physical parameters of the components. Optimum

18Preliminary Measurement of Solar and Atmosphere
Radiations with a New Experimental Set-up of Double
Copper Plate Structure
Y. Miyahara
New SUBARU, LASTI, University of Hyogo
Abstract
Solar and atmosphere radiations were measured with a new experimental set-up of
double copper plate structure on fine calm days. In contrast to the conventional apparatus
for all sky (global) radiation, there is no glass window in the set-up. The radiation analysisof measured data was performed in a simple clear algorism based on heat transfer byradiations. In spite of crude experiment, the results fairly well agree with the conventional
ones, and are explained consistently using the Rayleigh scattering of solar radiation by air
molecules with an atmosphere muddiness (turbidity) factor Rmud = 9.5, and similarly inregard to scattered radiation. However, it is not thought that the measured data are very
accurate, so that it is required to improve the set-up and measurement for more detailed
comparison. There is a large room to be improved.
1.

Introduction
In recent years, the warming climate on theearth is becoming a serious problem worldwide, sothat the reduction of CO2 and CH4 gases in theatmosphere has become an urgent task in all countries.
In fact, we experienced abnormal hot summer at atemperature as high as 35 Ԩ for about two weeks two
years ago. In the New SUBARU facility for asynchrotron radiation experiment equipped with anelectron storage ring, the temperature in theexperimental hall is controlled in the range of25~26 Ԩ by air conditioners. However, the electric
power required for this is close to a contract limit.
Accordingly, we have considered some measures forthe air-conditioning to decrease the power. In order to
see their effects beforehand, it is worthwhile tocalculate the temperature distribution in the building
before and after the measures.
Initially, we considered only the sunshine
energy (solar radiation) on the roof. However, it was
found that atmosphere radiation Qa = V0Ta4 (explainedlater) on the roof plays an important role to maintainthe hall temperature at a moderate level whole day. If
the radiation is not considered, the hall temperature
decreases substantially at night. Accordingly, anappropriate expressions of the solar and atmosphereradiations are required. However, their introductory
definitions and explanations found in Japaneseinternets are diverged in pieces, while discussions inarticles and textbooks are rough or very advanced anddetailed [1]. To get an approximate but physicallyconsistent description as a whole, we have made aradiation
analysis
basedontemperature
measurements, which were obtained by anexperimental set-up of double copper plate structure.
The structure was prepared because of the similarity
to the sunshine-on-roof problem.
The solar energy constant, Es0 = 1373 W/m2
outside the atmosphere, is reduced considerably byscattering and absorption when passing through theatmosphere, and the atmosphere at a thermal
equilibrium emits and reflects an infra-red radiation.
There are several types of special apparatus forthe measurement of these radiations; pyrheliometerwith a narrow window for solar radiation,pyranometer and pyrgeometer (infrared radiation
monitor) for all-sky (global) radiation. By
suppressing the solar radiation with a disk mask, thepyranometer can measure the scattered radiation.
Examples of the radiation energies measured by theconventional apparatus in Japan Meteorological
Agency are given in Table 1.
The solar radiation spectrum spreads out mainlyin the wavelength O = 0.3~3 Pm, and longer at alower level, with the peak at 0.5 Pm, while theinfrared radiation at 300 K spreads in the range O =3~60 Pm with its peak at 10 Pm. The top of
pyranometer is covered with a glass window (dome),
which is transparent up to 90 % almost in the samerange as the solar radiation, so that this apparatus,
when masked, is expected to measure the scatteredradiation only.
The analytical algorism of pyranometer is thatthe temperature difference between detector plate andbottom base, measured with a thermopile, is
proportional to the input of scattered radiation andinversely to heat transfer coefficient between them.

19

site

Table 1. Radiation energies measured with conventional apparatus
date4ҏ    Es
Essin4
Eall
Esc
Esc*
QIR
deg

2
W/m

2
W/m

2
W/m

2
W/m

2
W/m

2
W/m

W0

---------------------------------------------------------------------------------------------------------------------------Fukuoka 12/4
33
943
512
600
71
88
260 2.7
Tsukuba 3/17
55
771
632
857
228
225
260 5.1
Tsukuba 3/19
55
814
667
843
171
176
280 4.7
4ҏҏVRODUDOWLWXGH Es ; solar radiation, Eall ; all sky radiation, Esc ; scattered radiation, Esc* = Eall ҟ Essin4ҏH[SHFWHG
scattered radiation, QIR ; infrared radiation, W0 ; atmosphere muddiness factor determined from Es/Es0 (seeAppendix A). All data are at noon. Tsukuba and Fukuoka are about 500 km away in the East and West,
respectively, from the New SUBARU site.

The coefficient is mainly determined by theheat conductivity of support metal between the plateand base. The plate temperature is also affected by
the radiation from plate surroundings. Accordingly,
the transfer coefficient is carefully prepared, but its
details are not explicitly described [2,3]. There is agood agreement between the measured radiation andthe model-calculated one in the case of the solar
radiation. However, there are considerable differencesin some cases of scattered radiations [4-7].
Accordingly, there arose a question that thermalradiation of the glass window itself possibly affects
the detector of pyranometer [8], and several results
measured with pyranometers of different makers
were compared [9].
On the other hand, as described in detail in
section 2, the present set-up has no glass window,
while surrounded with a wind suppressor. The
measurement was performed on fine calm days ofApril 5th and 29th with no cloud in a light-blue sky,and no wind but with weak wind breathing. Plate
temperatures were measured with thermometers. The
structure is different from that of conventional
apparatus. There is no need to consider the window
effects, and the analysis is performed with an originalalgorism on the basis of heat transfer by radiations.
Related energies and heat transfer in and out of theplates are considered explicitly and analyzed as afunction of the solar altitude.

Fig.1. Experimental set-up of double copper plate
structure for solar and atmosphere radiation
measurements; (a) side view and (b) top view. The
set-up was placed in a dry-grass garden, on woodplates and corrugated board, and surrounded withcorrugated board boxes.

reflection on the copper plates.
The measurement was performed for 12:30 ~16:40, when the set-up was whole rotated graduallyclockwise in accordance to the sunshine direction.
The solar altitude 4 was determined by measuring
the shadow length of a square block placed on ahorizontal plane.

2.

Experimental set-up
The set-up is shown in Fig.1, which is placed
horizontally in a dry-grass garden. To avoid or reduce
the effects of wind and sunshine reflection fromsurrounding buildings, the set-up is about 10 m awayfrom an office house, 5 m high, in the East, and about
30 m away from an experimental building,
about 15 m high, in the North. There is no obstacle in
the South and West. The set-up is surrounded bycorrugated cardboard boxes with 460 mm high, being
closely connected to suppress wind effects. The
boxes in the opposite side against the sunshine arecovered with a dark-blue cloth to suppress sunshine

On the other hand, for the measurement of
atmosphere radiation in the garden, the set-up wasplaced in a shaded area, being produced by a whiteboard, 50x60 m2 wide, and attached against sunshine
on a three-leg support about 2 m high. The board andsupport were moved against the sunshine direction. In
this case the wind suppressor was not placed since
the weather was fine and very calm.

20

3.

Results and analysis
Figure 3 shows the expected transfer ofradiation energy in and out of the copper plate A per
unit area, where the downward radiation is composedof three parts; Es the solar radiation, Esc the scatteredradiation, and QIR the infrared radiation. In thepresent experimental set-up of wide plates with anarrow gap, it is assumed that the radiations between
the plates are emitted effectively in normal to theplates.
At first, we consider the shaded area
measurement made for t = 13:11 ~16:35, when a setof temperatures TA, TB and Ta at tj (j = 1~28) wereobtained. These temperatures at each set are mutuallyrelated as follows. At the equilibrium state, we havethe following equation,

Fig.2. Measurement of radiation coefficient of copper
plates. Temperatures of plate A and B measured byradiation monitor TradA and TradB, and those measured
by conventional thermometer TA and TB are shown
against nominal radiation coefficient Hn. True
coefficients HA and HB are determined at the point
where both temperatures agree.

Esc  QIRp AQA  pB QB  pH QH(1)with the following definitions,pA
pB[2  H A (1  H B )]

H B [1  (1  H A )(1  H B )] , pH
QA

QH

,

2 /HA

V 0TA ( K ) , QB V 0TB ( K ) 4 ,
H a (TA  Ta )4

where V0 is the Stephan-Boltzmann constant, and Ha
is the heat transfer coefficient between plate A andthe air around the plate. Symbol K indicates thetemperature unit of Kelbin. Heat transfer between theplates via air by conduction and convection isneglected since the heat conductivity of air is verysmall, and the air, slightly warmed between the plates,is thought to stream out before affecting the opposite
plate.
Now, let’s introduce an equivalent atmosphereradiation Qa0 in the sky as follows,(2)
Qa 0 yQa Esc  QIR

Fig.3. Radiations coming in and out of plates A and B.
Meaning of symbols are given in the text.
As for the set-up, copper plates were usedbecause of high heat conductivity for fasthomogeneous response to the gradual change of solar
radiation during the experiment. We tried to paint theplates with black color for complete absorption ofradiation, but not successful because of its smoothsurface. Instead, the radiation coefficient of the plates
was determined from the surface temperature, being
measured in a room with a thermal radiation monitor
as well as the conventional monitors attached to thesurfaces. Both surfaces of plate A are of dark orange
color, and those of plate B are of metallic-mirror
orange color.
Figure 2 shows the temperatures TradA and TradB
measured with the radiation monitor against thenominal radiation coefficient Hn as well as thetemperature TA and TB of plates A and B measured
with the conventional monitors. From the figure, theradiation coefficient is determined as HAҏ= 0.95 forplate A and HB = 0.90 for plate B. These nearly thesame coefficients were not expected beforehand since
plate B represents metallic mirror surface, but notplate A.
.

where Qa = V0Ta(K)4, and y is a constant to be
determined. When Eqs.(1) and (2) are combined, ycan be expressed as a function of Ha. Empirically, it is
known that Ha § 5 W/m2/K for no air stream and10~300 W/m2/K for air stream, so that we first
assume Ha = 5, 10 and 15 W/m2/K. Substituting
measured temperatures TA, TB and Ta at each set, we
obtain y = 1.040, 1.058 and 1.076, respectively. As
discussed later, however, Ha = 7.0 W/m2/K is themost probable in relation to the solar constant Es0,
and then y = 1.048 ± 0.006 is determined
Next, we consider the radiation measurement
under the sunshine. From the measured temperatures,
Qn’s are expressed as a function of X (=sin4) (seeFig.4). Some fluctuations of the data are observed in
the range of sin4 = 0.5~0.8, which are caused byweak wind breathing and partly by the stepwise
rotation of the set up as the sun moves. The weather
was quite calm beyond the above range.

21

and y = 1, we obtain Es0 = 1182, 1684 and 2187
W/m2 respectively. Thus, Es0 differs much at different
Ha. Note that Es0 should be equal to the solar constant1373 W/m2, for which Ha = 7.0 is obtained. At thesame time, y = 1.048 is determined as explained
above. Then, inserting numerical values of bn cn and
Pn in Eq.(7-b), we obtain Ds1 = 0.425 and Ds2 = 0.061.
Note that Es(X) can be expressed as

Es ( X )Now, we again assume the equivalentatmosphere radiation yQa as Eq.(2), so that we have

¦

pnQn

(3)

n A, B , H , a

Esc ( X )where the fourth term paQa with pa =ҏҟy/HA is added.
The experimental data Qn’s are fitted by the following
equations (see Fig.4),

an X  bn 

Qn ( X )cn
X

where an, bn and cn are obtained as
an
bn
Qn
QA
391.7
262.2
55.64
435.6
QB
478.1
ҟ152.8
QH
27.27
414.7
Qa

Qn
QA
QB
QH

cn
15.95

ҟ
21.18
ҟ

¦ an pn  n
n

n n

X

 n

X



2X 2

)

Esc 0 (1 

D sc1 D sc 2
X



X2

)

(9)

en
544.1
523.2
33.46

fn
gn
ҟ         
ҟ          64.82 ҟ

Note that QH in Fig.5 are expressed for Ha =100, so that eH, fH and gH should be multiplied by
0.070 for Ha = 7.0. Taking into account Eq.(1), we
have

Note that in the figure QH is plotted for Ha = 10, fromwhich above aH, bH and cH are determined.
Accordingly these values should be multiplied by K=0.5, 1.0 and 1.5 for Ha = 5, 10, and 15, respectively.
Combining Eqs.(3) and (4), we obtainEs ( X )) | Es 0 (1 

D s21

where Esc0, Dsc1 and Dsc2 are to be determined.
Expanding QA, QB and QH of experimental data
against 1/X (see Fig.5), the coefficients for Qn = en –fn/X + gn/X2 are obtained as follows,(4)¦b P ¦c P

X

D s1

(8)
We have Ds12/2 = 0.090, which is somewhat larger
than the above Ds2. However, the graphs of Es =Es0exp(ҟDs1/X) and Eq.(6) against 1/X are very close toeach other in the range 1/X = 1~3, or 4 = 90°~19 °.
Finally, we consider the term Esc + QIR
explicitly in the case of the shaded area measurement.
The measured temperatures TA, TB and Ta decrease as
the time. This is ascribed to the decrease of Esc as thesolar altitude 4, while QIR is nearly constant indaytime. Similarly to Es(X), we assume the following
X dependence of Esc,

Fig.4. Radiation energy QA, QB, Qa and QH measured
under the sunshine against X (=sin4), which are fitted
by Qn = anX + bn+cn/X.

Es sin 4

Es 0 exp(

D s1

n n

(5)

X2

Here, we assume the following reduction of solar
radiation,

Es 0 (1 

Es ( X )D s1 D s 2
X



X2

)

(6)

Then, Eq.(5) leads

Es 0¦a p ,
n

D s1



¦b p
n

n

Es 0

n

(7-a)

n

n

Ds2

¦c P

n n

n

Es 0

(7-b)
Fig.5. Radiation energy QA, QB, and QH measured in
the shaded area against 1/X (=1/sin4 , which are
fitted by Qn = en– fn/X + gn/X2.

Let’s consider Es0 of Eq.(7-a). Inserting
numerical values of an and Pn at Ha = 5, 10 and 1522¦ e p Q ,

Esc 0

n

n

(10-a)

IRn A, B , H

¦ fp
n

D sc1



n

n A, B , H

Esc 0

D sc 2

¦g P

n n

n

(10-b)

Esc 0

Assuming QIR = 270 W/m2 (see Table 1), we obtain
Esc0 = 296 W/m2 from Eq.(10-a). In addition, we
obtain Dsc1ҏ ҏ and ҏDsc2ҏ= 0.037 from Eq.(10-b).
Esc(X) is expressed as

Esc ( X )Esc 0 exp(

D sc1
X

) | Es 0 (1 

D sc1
X



D sc21
2X 2

)

(11)
Then, we have ҏDsc12/2 = 0.025, which is slightly
smaller than Dsc2.
4.

Discussion
Here, we consider the reason of reduction factor*(X) = exp(ҞҏҟDs1ҡX) of the solar radiation. It is known
that the pressure of atmosphere decreases as theheight, z, from the earth surface, so that theatmosphere density is expressed as(12)
U ( z ) U0 exp( P z )with U0 = 1.526 kg/m3 and P = 0.1445x10ҟ 1/m in thestandard state of P0 = 1 atm and Ta = 15 Ԩ. The
sunshine is scattered and absorbed by various
molecules and aerosols in the atmosphere during thepass, which is proportional to the density.
Accordingly, the solar radiation varies as

dEs
dZ p

 E Es U0 exp( P Z p sin 4)(13)

where Zp (§ z/sin4ҏ for 4 > 20°) is the pass length of
the sunshine ( see Fig.6), and E is a constant to be
determined. Integrating for Zp = 0 ~ , we obtain thefollowing relation ҏDWWKHHDUWKVXUIDFH,

Es ( 4 )Es 0 exp(EU0

P sin 4)a similar expression of the reduction as Eq.(8) with Ds= 0.108 for Es0 = 1373 W/m2.
Since the solar radiation is further absorbed
and scattered, by the gases and aerosols, atmospheremuddiness (turbidity) factor Rmud is conveniently
multiplied to the cross section. Then, Ds is increased
to 0.300, 0.412 and 0.434 with Rmud = 5, 9 and 10,
respectively, so that Rmud = 9.5 is appropriate. The
definition of coefficient Rmud is similar to thecoefficient W0 given in Table 1 (the definition is given
in Ref.10).
The scattered radiation by the Rayleigh process,also discussed in Ref.10, can be expressed similarlyas Eq.(11) with Esc0 = 64 W/m2 and Dsc = 0.40 for
Rmud = 1. It is imagined that the scattered radiation
arrives at the earth surface through a more
complicated process, so that two muddiness factors
are assumed; RmudA is multiplied to the crosssection for the scattering in the initial process
before the scattering, and RmudB is multiplied
to the one for the relevant scattering. Then, we
obtain RmudA = 0.25 and RmudB = 3.5 as the mostprobable values for the experimental values
Esc0 = 296 W/m2 and Dsc = 0.224.
It is required to consider the Mie scattering by
aerosols, which is effective in the case when the sol
size is nearly the same as the sunshine wavelength.
However, it is very complicated and requires detailed
information of aerosols.
As shown with Eqs.(8) and (11), thepresent results on Es and Esc are expressed as afunction of 4, or the sun altitude, so that the these
expressions can be applied to any case of all seasons
if similar fine calm days are assumed. Then, Es andEsc at 4 = 55 ° are estimated and compared with thedata given in Table 1. The solar radiation is Es =
817 W/m2 with the muddiness factor Rmud = 9.5,
compared with Es §:P2 andҏW0 §DW7VXNXED (14)Comparing with Eq.(8), we have Ds1 = EUP, and E =4.0x10-5 m2/kg for Ds1 = 0.425. This E isapproximately expressed as E§Vt/Mm for a constantcross section Vt and molecular weight Mm.
It is known, however, that the reduction
process is very complicated. It is reduced by theRayleigh scattering due to the air molecules N2 andO2, by the absorption due to trace gases such as ozone,
H2O, CO2, CH4, etc, and by the Mie scattering andabsorption due to aerosols such as vapor-water andmicro-dust.
In Ref.10, the Rayleigh scattering of the solar
radiation is discussed in detail. The scattering iseffective in the case that the molecular size is smaller
than the wavelength. The cross section depends muchon the wavelength, and as shown in Ref.10, we obtain

Fig.6. Relation of the height, z, in the atmosphere,
and pass length, Zp, of sunshine at the experimental
point on the earth surface. 4 is the sun altitude fromthe horizontal plain.

23

Note added in proof; The results of this work wasapplied to the following paper “Investigation of
measures against hot summer for energy reduction
and temperature stabilization in the New SUBARU
experimental building” [11].

Similarly, the scattered radiation is Esc = 225
W/m2, compared with Esc §200 W/m2 at Tsukuba. We
see the both values are fairly close to each otherexcept for Rmud and W0. For more detailed comparison,
it is necessary to make the both measurements on afine calm day at the same time at the same place.

References[1] M. Aida, “Atmosphere and radiation process” inJapanese, (Tokyo-do, Tokyo), Chap.1~6 (1982).
[2] Y. Hirose and M. Shimomichi, MeteorologicalSoc. of Japan, 185: 73-104 (1996)[3] Y. Miyake, J. Japan Solar Energy Society, 35:
No.2, 61-72; No.3, 57-65 (2009).
[4] S. Kato, et al., J. Geophys. Res., 102: D22,25881-25898 (1997).
[5] R. N. Halthore, et al., J. Geophys. Res., 102:
29991-30002 (1997).
[6] R. N. Halthore, et al. Models overestimate
diffuse clear-sky surface irradiance: A case for excess
atmospheric absorption. Geophys. Res. Lett., 25:3591-3594 (1998).
[7] R. N. Halthore and S. E. Schwartz, J. Geophys.
Res., 105: D15, 20165-21077 (2000).
[8] B. C. Bush, et al., J. Atmos. Ocean. Tech., 17:165-175 (2000).
[9] J. Michalsky, et al., ARM Science Team
Meeting, St. Peterburg, Florida, 7-1 (2002).
[10] Y. Miyahara, this report, Numerical study on
the Rayleigh scattering of solar radiation.
[11] Y. Miyahara, Y. Takahara and S. Kamiue,
Humans and Nature, 23, 81-93 (2012) in Japanese.

In conclusion, the initial purpose of this study
described in section 1 was nearly achieved, but notvery satisfactorily in regard to the accuracy. The
present experiment on the solar and atmosphereradiations was performed with a new experimental
set-up of double copper plate structure. The set-up
has no glass window, and the analytical algorism ofexperimental data was clearly described using
radiation transfer scheme, which is different from theconventional one. It is noteworthy that in spite ofsimple set-up and measurements the present results
are not much different from the conventional ones.
However, we cannot make detailed comparison
between them since the measurement is not very
accurate and the measured conditions are not thesame. It is required to improve the experimental
set-up and measurement conditions for more precise
measurements.

Acknowledgement
The author is grateful to Dr. O. Ijima of the
Aerological Observatory for valuable information.

24

Numerical Study on the Rayleigh Scatteringof Solar Radiation
Y. Miyahara
New SUBARU, LASTI, University of Hyogo
Abstract
The solar radiation from the sun to the earth decreases when passing through theatmosphere. The reduction is numerically calculated assuming Rayleigh scattering by theatmosphere molecules. For further reduction of the radiation by the scattering andabsorption due to aerozoles and others, Linke’s muddiness factor is introduced. Similarly,
the scattered radiations by the Rayleigh’s process and others are also discussed.
The cross section of Rayleigh scattering depends
on the scattering angle \ as FR(\) = (2/3)(1+cos2\For simplicity, however, we assume isotropic
scattering, with the following total cross section [3],1.

Introduction
Experimental results of solar and scatteredradiations were given in Ref.1, which is discussed
theoretically in the present work. The solar radiation isscattered by the molecules such as N2 and O2 in theatmosphere when passing through the atmosphere. The
scattering cross section by the molecules is given by
the Rayleigh’s formula, which depends on therefraction index and density of atmosphere. The
density U [kg/m3] as well as pressure P [hP] andtemperature T [K] of the atmosphere vary as the heightz [m] from the earth surface, which are approximately
expressed in the range z = 0 ~ zmax (= 20 km) as

VR (O, z)

N ( z )V R (O , z )
dz ]
sin
4
0

zmax

F (O , 4) exp[ ³(1-c)

The number density of air molecules is given by N(z)= Uz/Mm, where Mm = 28.8*10-3mp with mp the protonmass.
The refraction index n (= 1 + 'n) depends on the
wavelength O Pm), being given by [2]'n ( O , z )u (O ) d O

HP
C P (1  PG )(1  0.16 v )
8
T
P
10

683939.7
4547.32371.34 2
130  O
38.9  O 2(2-b)

9.325 u 10
0.25844
G (T ) 57.9 u10 TT2

Es (4)³ u (O )F (O , 4)d O(6)0

By numerical integration at several 4’s, we obtainEs(4), from which we obtain Ds= 0.115 ~0.081 in therange 4= 90 ~ 20 ° for the expression Es(4) =Es0*exp(Ds/sin4) with Es0 = 1373 W/m2. Especially,
we have Ds =0.108 at 4 = 55°. This is very small
compared with the experimental result of Ds1 = 0.425
at 4 = 55 ° [1].
The solar radiation, being additionally absorbed(2-c)
where H (0.5 assumed) is the humidity and Pv[hP] isthe saturated vapor pressure, given by
7.5TC

Pv (TC ) 6.11u10TC  237.3

(5)

Omax

4

8

3 GO
O [exp(D 0 / OTs )  1]
5

where D0 = hc/kB and 3= 2Shc2Jwith J= (Rs/Des)2 ; h,c, kB are conventional, and Rs = 6.969x108 m the sun
radius and Des = 1.496x108 m the distance between theearth and the sun. The spectrum spreads out in therange O= 0.3~3 Pm. Numerical integration of u(O)over O agrees with the solar energy outside theatmosphere; Es0 = JV0Ts4 = 1373 W/m2.
Then, the solar energy at the earth surface iscalculated by(2-a)

C (O )(4)

Because of the k4 dependence of VR(O,z), shorter
wavelengths are much more scattered.
Meanwhile, the solar radiation is regarded as theblackbody radiation at temperature Ts = 5780 K at thesun surface, and the spectrum outside the earth
atmosphere is given by(1-b)

U 1.5264 exp(0.14467 u10 z )(3)where k = 2SO. Taking into account Eq.(14) of Ref.1,
we have the following reduction factor of the solar
radiation,

P 1013exp(0.14467 u103 z )(1-a)
3T 289.45  8.9278 u 10 z  0.25937 u 103 z 2
3

2 k4'n3S N(z)2(2-d)

with TC =T(K) 273.2.
2. Reduction of solar radiation25

and scattered by gases and aerosols, is further reduced.
After Linke, this reduction is taken into account by
multiplying atmosphere muddiness factor Rmud to thecross section VR. Then, Ds at 4 = 55 °is increased to0.300, 0.412 and 0.434 with Rmud = 5, 9 and 10,
respectively. Accordingly, Rmud = 9.5 is the optimum.
Linke’s definition of the reduction factor WG isexpressed as

Esc (O , 4)1

u* s ( z , 4)rdrdzdI(9)

where *s(z,4) represents the reduction factor of initialsolar radiation at z, given by* s ( z , 4) exp[ D inj ! ( zmax  z )sin 4] ..(10)To save CPU time, the average <Dinj> for D(O, z) =N(z)RmudAVR(O, z) is introduced as, D inj (O , z ) !

uD [O ,

where LR is the optical length at m = 1 for Rayleighscattering at the standard state (with pressure P0), Lg
and La are the optical length for gas absorption, and foraerosol scattering and absorption, respectively. Notethat m ؆ 1/sin4. This WG is determined using measured
Es and P together with calculated LR. We see that there
is a relation of WGLR  Ds. Note that WG is further
modified to W0 as follows, so that W0 is close to WG.

P LR (m 1)
P0 LR (m)N ( z ) RmudBV R (O , z )u (O ) z
4S d 2
d
1

³ ³ ³
0

P
(7-a)
Es Es 0 exp( LRW G m)
P0
L  La P0
WG 1 g
(7-b)
LR P
1
㧝
m
sin 4 1  (1/ 35)(1/ sin 2 4)W 0 1  (W G  1)

2S zmax rmax

kmax

1

k 1

max

¦(k

)

(kmax  k ) z  (k  1) zmax]
kmax  1(11)

Here we have assumed atmosphere muddiness factors
RmudA and RmudB for the initial radiation and scatteredradiation, respectively. Integrating numerically, we
obtain Esc(O4). Finally, summing up over Oat several
4s and applying the form of Esc(4) =Esc0exp(Dsc/sin4), we obtain Esc0 = 64 W/m2 and Dsc =0.40 for RmudA = RmudB = 1. Experimentally, we have
Esc0 = 296 W/m2 and Dsc1 = 0.224, which can be fitted
by RmudA = 0.25 and RmudB = 4.
Meanwhile, there is another possibility of4dependence of Esc. Let’s consider the angulardependence FR(\) = (2/3)(1+cos2\) of the scattering
without reduction of initial radiation before scattering.
In Fig.1, the directions of initial radiation andscattered radiation toward the origin are expressedas ns cos4sin4) and nsc = (sinTcosI, sinTsinI, cosT),
respectively, so that the scattering angle is given by(8)

3. Scattered radiation
Next, we consider the scattered radiation using theRayleigh’s isotropic cross section. Supposes that thesolar radiation comes from the y direction at the solar
altitude 4, and collides with a molecule at a point of (r,z, I) in the cylindrical coordinate with a distance d =(r2+ z2)0.5 from the origin (see Fig.1). The total
scattered radiation arriving at the origin, normal to thehorizontal plane, can be calculated-by,cos\

cos 4sinT sin I  sin 4 cos T(12)When, the cross section of scattered radiation ismultiplied by RmudC = 3.5, we obtain Esc0 = 316 W/m2
and Dsc = 0.054, which is, however, very small
compared with Dsc1 = 0.224. Thus, the effect of FR(\)
is negligible.
Above values are nearly saturated for rmax = zmax
= 20 km and kmax = 5. It is confirmed that the spectrumof scattered radiation represents narrow peaks aroundO = 0.4 Pm, agreeing with the blue sky. It is also
confirmed that the peak spectrum of solar radiation
shifts from O = 0.5 Pm at 4 = 90 ° to 0.75 Pm at 4 =10 °, as we see the red sun at sunrise and sunset.
References[1] Y. Miyahara, This report, Preliminary measurementof solar and atmosphere radiations with a newexperimental set-up of double copper plate structure.
[2] J. C. Owens, Applied Optics, 6: 51 (1967).
[3] J. D. Jackson, “Classical Electrodynamics” (Jhon
Wiley & Sons, New York) p421 (1962).

Fig.1.
Rayleigh scattering of sunshine in thecylindrical coordinate on the earth surface,
representing isotropic and elliptical distributions of
scattered radiation. The sunshine comes in the y
direction at sun altitude 4.

26

Geometric Luminosity for the Angled Collision of
Asymmetric Beams with Hourglass EffectYoshikazu MIYAHARA*

New SUBARU, LASTIAbstract
The geometric luminosity of angled collision of asymmetric beams with different Gaussian
distributions is given in a compact formula.
Recently, we have discussed geometricluminosity of angled collision of strongly focused
beams with different Gaussian distributions [1]. To
treat the hourglass effect naturally, we haveintroduced a pseudo-isotropic beam model, in which
the trajectories of colliding particles are curved
similarly to the beam size variation along the
propagation axis (see Fig.1), where the collisionconditions of particles P1 and P2 are clearly
determined. At a horizontal collision angle of 2I, thereduction factor of the luminosity against the head-on
collision can be expressed as
f

cos I

RACHG

³

exp(hZ c2 )S  V z2 ! f 1 Vx Z c2 1 Vy Z c2             2!
 U x,y,*2
 V x,y !

 Vx,y U x2 !

RACHG
,

2

              

W xz

Vx

V !
,
cos I
2
z
2

W yz

Vy

(2)

V !
.
cos I
2
z
2

Let’s make the following approximations. First,
2in the exponential term we assume 1 W xz t | 1
since it is observed in numerical examples thatRACHG is little affected by this term. Second, thedenominator is assumed as

dZ c
(1)

V1x*2 V *2
2x
 *2
*2
E1x E 2x­ ª  V 2 ! tan 2I º ½
zt 2 ¾
exp®«1
2 »
*2
f
1
¯ ¬  V x ! (1 W xz t ) ¼ ¿
dt
³
S f
1 W xz t 2 1 W yz t 2

1 W xz t 2 1 W yz t 2 | 1 Wt 2
with W,W xz  W yz . Then, Eq.(2) is expressed ascos2 I ª  V z2 ! tan 2I º
,
«1
2 »
 V z2 ! ¬  V *2
x ! (1 Vx Z c ) ¼hwhere V ix and E ix are the i -th horizontal beam
size and beta function at the center of collision point,
V z is the bunch length, the symbol < > denotes the**average of colliding beams, and  U y ! is similar
2

to  U x ! . This equation, fairly precise, can beapplied to any cases of synchronous angled collisionof asymmetric beams which strongly focused.
Numerical estimation of Eq.(1) is rather easy
today with the aid of conventional computer, but for
simplicity, we try to express it in a compact formula.
2

Fig.1. Angled collision of asymmetric beams at ahorizontal crossing angle ITrajectories of particles
P1 and P2 are curved similarly to the beam size
variation along the propagation axis and collide at Q.

Changing the variable from Zc to t, we have

27

*
RACHG
|

f

1

³

exp(s2 )S A f 1 Bs2

 V z2 !
A 1
tan 2I ,*2 Vx !

B

ds,

(3)

W
.
A

If W xz  1, then RACHG is very close to RACHG .
Meanwhile, the integral of Eq.(3) has been
considered in Ref.[2], and expressed as
*

*
RACHG
|

1

S AB

exp(

1
1
)K 0 ( ) ,
2B
2B

(4)

where K 0 is the modified Bessel function of orderzero.
Figure 2 shows numerical examples of I
dependence of reduction factors RACHG of Eq.(1)and RACHG of Eq.(4) for the e+ҟHҟ collision in PEP II
and for a tentative laser-electron beam collision,
parameters of which are given in Ref.[1]. It isobserved that factors RACHG and RACHG* agree very
well in both cases, but there is a slight difference inthe case of laser-electron beam collision. This isbecause W xz is negligibly small in the former casebut not in the latter case, as indicated in the figure.
*Fig. 2.

Angle dependences of reduction factors*
RACHG and RACHG
are shown for the cases of e+ҟHҟ

collision of PEP II and for a tentative laser-electron
collision. In the figure, Itis ҏWKH WUDQVLWLRQ DQJOH
above which the hourglass effect becomes lesseffective.
References[1] Y. Miyahara, Nucl. Instr. Methods Phys. Res. A,
588/3 (2008) 322.
[2] G. E. Fischer, SPEAR-154, 1972 (unpublished).
[3] K. Hirata, Phys. Rev. Lett. 74 (1995) 2228.

In a special case of symmetric beams,
horizontally flat and vertically focused, we have*isW xz  1 and W | (V z / E y ) 2 . Then, RACHG
reduced to an existing formula [3].

28Observation of Smith-Purcell radiation in Terahertz
regime at electron linear accelerator LEENA
S.Hashimoto, S. Chin, K. Kawata, Y. Minagawa#, Y. Takemura#, D. Li*, S. Amano, S. Miyamoto
LASTI, University of Hyogo
#
JASRI
*
Institute for Laser Technology
Abstract
Terahertz radiation by the Smith-Purcell effect was successfully observed using 15 MeV electron
beams of the linear accelerator LEENA. The radiation properties such as the angular dependenceof peak wavelength were measured. Wavelength spectrum measured by the Martin-Puplettinterferometer is very clear and the peak wavelength well corresponds to the calculated one.
Introduction
In order to develop high peak power, wide range (0.1-10 THz) and tunable terahertz radiation sources
using relativistic electron beams, we have been upgrading the compact electron linear accelerator LEENA[1-5]. The electron beams with bunch length shorter than the wavelength of emitted light can generate highpower radiation by coherent radiation. The main parameters of LEENA are shown in Table. I. In addition
to the synchrotron radiation from a bending magnet, the Smith-Purcell radiation from a metal grating platenear an electron orbit was successfully observed. The spectrum of Smith-Purcell radiation was measured
with the Martin-Puplett interferometer. In this paper we report the present status of the Smith-Purcell
radiation in a terahertz regime.
Table I

Fig.1 Observation of Terahertz radiation using
LEENA electron beams; synchrotron radiation andSmith-Purcell radiation.

Main parameters of LEENA.

Beam energy
Macropulse current
Macropulse width
Repetition frequency
Gun
CathodeBunch length

6-15 [MeV]
100 [mA]
5 [us]
10 [Hz]RF gunLaB6 (thermal)~30 [ps]

Experimental results of Smith-Purcell radiation
The copper plate with grating period of 10 mm is equipped in a vacuum chamber of the LEENA. Using
three mirrors located in the chamber, terahertz radiation can be extracted into the air through a quartz
viewport. The Smith-Purcell radiation in a terahertz regime was measured with a Zero Bias Detector.
Measured radiation power is about ten micro Watt. Because present bunch length is longer than terahertz
wavelength, the measured radiation is incoherent.
The emitted wavelength of Smith-Purcell
radiation has an angular dependence, i.e., shorter
wavelength light is radiated in the forward direction
and longer wavelength in the backward direction.
The mirrors in the chamber can rotate according to
the desired angle for measurement. Fig. 2 shows
the angular dependence of radiation power
measured by the two detectors with different
measurement ranges.
The calculated emission
angle for the light of 0.075-0.11 THz is about 40
Fig.2 Observation of angular distribution ofdegrees and for 0.11-0.17 about THz 50 degrees.
Smith-Purcell radiation power.
Two detectors
Experimental results show a good agreement to thewith different measurement ranges are used:
calculation.
0.11-0.17 THz (upper) and 0.075-0.11 THz (lower).

29

Smith-Purcell radiation spectrum measured by Martin-Puplett interferometer
In a terahertz regime, the wire grid reflects theradiation component whose direction of thepolarization plane is parallel to the wire andtransmits the perpendicular component.
The
Martin-Puplett interferometer uses wire grids as adivider of terahertz light as shown in Fig. 3. Theinterferogram made from a path length difference
between two lights by moving a mirror wasmeasured with a ZBD. By the Fourier transformof this interferogram data, the wavelength
spectrum of Smith-Purcell light is obtained asshown in Fig.4. Measured peak wavelength ofSmith-Purcell light is 3.4 mm and is wellcorresponding to the calculations.

Fig.3 Martin-Puplett InterferometerFig.4 Interferogram of Smith-Purcell radiation measured with Martin-Puplett interferometer (left)
and its FFT result (right).

Summary and Future plan
The Smith-Purcell light was successfully observed at LEENA accelerator. The observed terahertz
radiation is incoherent, that is the electron bunch length is longer than the light wavelength. If the bunch
length becomes shorter than the light wavelength, coherent radiation occurs and radiation intensity becomesseveral orders higher. To make electron bunch shorter using an alpha magnet effectively, new solenoid coilis under construction just after the electron gun to suppress beam divergence. The emission angle ofcoherent Smith-Purcell (CSP) radiation depends on the electron bunch length. Thus CSP is not only apowerful terahertz light source but also a useful beam monitor for electron bunch length in linear
accelerators.
And the construction of new terahertz beam-line for user experiments will be started in the summer of2013.
References[1] S.Hashimoto et al., Lasti Annual Report, 12, pp.13-14 (2010).
[2] S.Hashimoto et al., Lasti Annual Report, 13, pp.11-12 (2011).
[3] S.Hashimoto et al., The 8th Annual Meeting of Particle Accelerator Society in Japan (2011).
[4] S.Hashimoto et al., The 9th Annual Meeting of Particle Accelerator Society in Japan (2012).
[5] S.Chin et al., The 9th Annual Meeting of Particle Accelerator Society in Japan (2012).

30

Energy calibration of electron beams by laser Comptonscattering γ-rays at BL01
H. Utsunomiya1, T. Shima2, K. Takahisa2, D.-M. Filipescu3, O. Tesileanu3, I. Gheorghe3, H.-T. Nyhus4,
T. Renstrøm4, Y.-W. Lui5, Y. Kitagawa6, S. Amano6, S. Miyamoto6
1Konan Univ., 2Osaka Univ., 3IFIN-HH Romania, 4Univ. Oslo, 5Texas A&M Univ., 6LASTI-UH
Abstract
We have calibrated electron beam energies in a nominal energy range 550 - 974 MeV using laserCompton scattering γ-ray beams at the synchrotron radiation facility NewSUBARU. The γ-ray
beams were produced at energies from 562 keV to 1727 keV and detected with a high-purity
germanium detector. The electron beam energies were determined by reproducing the full energy
peaks of the γ-ray beams by Monte Carlo simulations with a precision of 0.068% in 1σ.

III.
A.

RESULTS AND DISCUSSIONS

Energy calibration of electron beams(1)
where εL is the energy of a laser photon, mc2 is therest-mass energy of an electron, θ is the scattering
angle of the laser photon with respect to the electron
beam, and γ is the Lorentz factor of the relativistic
electron which is defined by γ =Ee/mc2 with the total
electron energy Ee. For simplicity, the collision

2

3000
2500
2000
1500

γ

Experiments
and Results
B. Linearity in the response of a LaBr3 (Ce)Low-energy
LCS toγ-raydetector
LCSbeams
rays were produced
below 2 MeV with a grating-fixed CO2 laser (wavelength λ=10.59 µm). Electrons were injected from a
LCS
beams werewith a Nd:YVO
linear-ray
accelerator
intoproduced
the NewSUBARU
storage4 laser
ring( =1064
in collisionsof thelaser
photons on
at thenm)
nominalenergy 974
MeV,
decelerated
to elec950
trons
at nominal
714toandandMeV,
and sub- energies
sequently753,
down
550 677
MeVMeVin steps
measured
with
a
LaBr
(Ce)
detector(3.5”
indiameter⇥3of 50 MeV. The LCS γ-ray beams were measured
4.0” in length, BrilLanCe380 89S102/3.5, Saint-Gobain)
with a coaxial (64 mm in diameter × 60 mm inat the count-rate less than 10 Kcps with a bias voltage
length ) high-purity germanium detector (HPGe). The
of +400 V and a shaping time 0.5 µs of a NIM amplienergy of γ-ray spectra was calibrated with thefier module. The -ray energy was determined by Montestandard γ-ray sources, 60Co including the sum peak,
Carlo simulations with the calibrated energy of the elec133Ba, 137Cs, and 152Eu and a natural radioactivity
tron beam as discussed in Sec. IIIB. The linearity in the
40K. The energy calibration was carried out before
response of the LaBr3 (Ce) detector to low-energy rays
and after the measurement of LCSγ-rays. From thewas investigated with the standard -ray sources, 60 Co,
γ-ray spectra, we determined absolute
133 calibrated
Ba, 137 Cs, and 152 Eu and an Am-Be neutron source
values of the electron beam energies by means of
as a 4.4 MeV -ray emitter.
Monte Carlo simulations in a nominal energy (Een)range 550 – 974 MeV.

Figure 1 shows results of the energy calibration
for the HPGe detector carried out before themeasurement of LCS γ-ray beam. The best linear fit
to the data gives a relation between the γ-ray energy
Eγ in keV and the channel number X by Eγ =0.3624X-0.8022. The data taken after the LCS γ-ray
measurement gives the same slope coefficient and anintercept -0.7458. The uncertainty of the energy
calibration is 0.08% in 1σ in the energy range 120
keV – 2.5 MeV. The electron beam energy wasdetermined by Monte Carlo simulations that best
reproduce the experimental γ-ray spectra measured
with the HPGe detector. The simulation code
incorporates the production process of γ rays in the
inverse Compton scattering into the EGS4 code [4]which simulates interactions of photons with thedetector material.
The energy of the LCS γ rays is given byE [keV]

Introduction
In the NewSUBARU, electrons are injected froma linear accelerator into a storage ring and undergo a
top-up operation at the nominal energy 974 MeV. The
storage electrons can be either accelerated up to 1.5
GeV or decelerated down to 0.5 GeV. Recently, a
new γ-ray experimental hutch, GACKO (Gamma
Collaboration Hutch of Konan University), was built
at NewSUBARU-BL01 and has become fully
operational. Quasi-monochromatic γ-ray beams canbe produced in the energy range 1 - 76 MeV by thelaser Compton scattering. The capability of tuning
the electron beam energy between 0.5 GeV and 1.5
GeV is important to nuclear physicists who use thelaser Compton scattering (LCS) γ-ray beams [1, 2].
However, the nominal energy of electrons isdetermined only with 1% uncertainty based on the
beam optics of the storage ring [3].
We calibrated the electron beam energy by
producing low-energy LCS γ-ray beams with a CO2
laser, where γ-ray energies are in the range of thestandard γ-ray sources. This report presents theenergy calibration for electron beams stored in astorage ring NewSUBARU at nominal energies
between 550 MeV and 974 MeV. The absolutecalibration of the electron beam offers an opportunity
to calibrate the energy of LCS γ-ray beams.

1000
500
0

0

1000 2000 3000 4000 5000 6000 7000 8000
Channel Number

FIG. 1. Energy calibration of the HPGe detector withthe standard γ-ray sources. The solid line is the best

FIG. 1. (Color online) Energy calibration of the HPGe delinear fit to the data.
tector with the standard -ray sources. The solid line is thebest linear fit to the data.

31 that emits rays inside a solid angle subtended by a 2
mm (in diameter) collimator made of 10 cm thick Pb.
Figure 1 shows results of the energy calibration for
We introduce an e↵ective source size in circular shape.

3

400

CountsCountsCountsCountsΔ
Δ

CountsCountsCountsCountsΔ

Countsbetween laser photons and electrons is assumed to
14
take place at a point where the (a)electron beam forms a
300
narrow waist in the beam optics. The collision point
12with a maximum collision efficiency is located at a200distance of 887cm for the CO2 laser (λ=10.59 µm)
10photons from a collimator and at 1847 cm for the
100Nd:YVO4 laser (λ=1064 nm) photons [2]. The
8electron beam size, which is smaller than the photon
0beam size at the collision point, determines the size
1600
1650
1700
1750
of a light sourcethat emits
γ rays inside
a solid angle
6
E [keV]
500
600
700
800
900
1000
subtended by a 2γ mm (in diameter) collimator made500
NominalEnergy[MeV]of 10 cm thick Pb. We introduce an effective source
electron beam spot is
FIG. 3. The difference ∆E of the real energy Eer from400size in circular shape. The (b)circular at the collision point for 10.59 µm photons of
the nominal energy Een of the electron beams: ∆E = EerFIG. 3. (Color
online) The di↵erence E of the real energynEpolynomial fit to thee . The solid line is the 4th-order300the CO2 laser but is elliptic for 1064 nm photons of r
thenominalenergy Een of the electron beams: E
Ee from
data.
See
text
for
details.
the Nd:YVO4 laser [2].
= Eer - Een . The solid line is the 4th-order polynomial fit to200
Monte Carlo simulations were carried out to the data.
Seeassociatedtext for details.
energywith the simulation was 0.1%.
reproducetheexperimental
γ-ray
spectrawith
two
Together
with
the
0.08%
uncertainty arising from the100
fitting parameters, the effective source size (ζ) andenergy calibration, the γ-ray energy was determined
gives 0.128% uncertainty, which corresponds to0the electron beam energy. It is to be noted that the data with
1200
1250
1300
1350
energy resolutionof the
HPGe detector
was taken
0.064%
uncertainty in electron beam energy.
E [keV]
into account as anγ energy spread of the electron beam
Figure 3 shows ∆E= Ener 4– Een, the difference
of
10
n 3
8000in the Monte Carlo simulations. The energyr(E) +1.302 ⇥beams
10 6 (E
E
=
4.695
⇥
10
the real energy Ee of etheelectronthuse)3
n from thedetermined
simulation
resolutionofthe HPGe detector
12.5
1.360by⇥ the
10 Monte(Een )2Carlo+ 0.6385(E103.94. (2)(c) was 6.7 keV (0.5%)e)
6000in full width at half maximum (FWHM) for 1332
nominal energy Een as a function of Een. The 4thpolynomial
to the in
data
gives
keV γ rays (60Co). Following the relation (∆Eγ/Eγ) ≈ Here order
MeV.
E and
Een arefitgiven
40002(∆Ee/Ee) based on Eq. (1), the detector resolution An attempt was made of experimentally detecting then 3∆E threshold= −4.695 × for
10−10(Eenlocated)4 + 1.302
10−6(EMeVe )was incorporated into the simulation as (∆Ee /Ee ) ≈ neutronAu
at× 8.072[5]. A−3(E n)2 + 0.6385(E n) − 103.94−1.360×10(2)ee
20000.1% in the standard deviation of Gaussian function. disk of 2mm-thick Au was irradiated with the LCS -ray
Examples of the best fits to the spectra are shown in beams
produced
the Nd:YVO4 laser at the nominalnHere∆E and Ewith
e are given in MeV.
energies
fromof677
to 661 in stepsof 32 MeV.
0Fig. 2. The full energy peaks were well reproduced electron-beam
An attempt was madeexperimentally
detecting
3540
550 Carlo simulations
560
570 the effective By changing the electron-beam energy by 2 MeV,by the Montewiththe neutron threshold for Au located at 8.072 MeV weE[keV]
source size ζ=0.9γ – 1.1 mm. The uncertainty in γ-ray changed
thedisk-ray
energy by Au
⇠ 50
keV.
Neutrons[5]. Aof 2mm-thickwasirradiatedwithwere
the detectedwitha 4⇡beams
triple-ringneutrondetector[6].4 laser
StatistiLCS
γ-ray
producedwiththe
Nd:YVO
400
400
14
14 events
the nominal
electron-beamenergiesfromto folcally atsignificant
were observed
above
667677
MeV
FIG. 2. (Color online) 300(a) Monte Carlo simulation(dotted
(a)
661
in
steps
of 2 MeV.
Bythreechanging
theenergies,
electron- 665,
(a)
lowed
by
no
net
countsatthelowestr300line) with an electron beam energy Ee =982.2 MeV for LCS
12
12 byIn
beam661
energy2 MeV,
wethe
changedthe γ-rayenergy-rays
663, andMeV.
view offact that
the LCS
laser
incomparison
with-ray spectra produced with
a
CO
2
200
by
∼
50
keV.
Neutrons
weredetected
witha4π
200 line) taken at the nominal energy
at the thresholdenergy for Au are produced tripleby 676.52
the experimental data (solid
10
10
ring
neutrondetector[6].energy
StatisticallysignificantnMeVelectrons,
thenominal
of
667
(665)
MeV is,
as
(a),
but
for
a
simulation
with
Ee =974 MeV. (b) The same
100
eventslarger
were observed
above
667
MeVMeV.
followedby it
100
in reality,(smaller)
than
676.52
Namely,with the data at Een =850 MeV.
Eer =860.7 MeV in comparison
8
nonet
countsatthethreelowestenergies,
665,
663,
8
r
(c) The same as (a), but for
turned out that the di↵erence between the real and nom0 a simulation with Ee =559.6 MeV
0
and 661 MeV. In view of the fact that the LCS γ-rays
n1650
1600
1700The result
1750 of=550 MeV.
in comparison with the data
inal energies
is6 larger energy(smaller)than
9.52produced(11.52) MeV
1600 at Ee 1650
1700
1750
at the thresholdfor
Au 900areby at
E [keV]
6500
600
700 (665)
800 MeV.
1000 present cali[keV]
a reproducibility test is also shown byEγtheopen circles afterthenominalenergy
of
667
The
500
600
700
800
900
1000
γ
676.52 MeV electrons,
the nominal
Nominal Energy[MeV] energy of 667
multiplied by a factor of500
12.5. See text for details.
500
NominalEnergy[MeV]
brationgives
thedi↵erenceof 10.44
MeV (10.43
MeV) at
(665)
MeV
is,
in
reality,larger(smaller)
than 676.52
(b)
400
(b)
the nominal
energy667of(665)
MeV. Thus, detection
the result of
400
MeV. Thus,
the ofresultthe experimental(Coloronline)The di↵erenceof the realthresholdenergythe for
theFIG.
experimental
detectionofAutheisEEneutron
of 3.
the
neutronthresholdfor
consistentFIG.
3. (Color
online)The di↵erenceof the real withenergy300
Eerr from the nominal energy Eenn of the electron beams: E
300
from
the
nominalenergyEoftheelectronbeams:E
E
In this measurement, use was made of a Pb collimatorcalibration.
Au=isepresent
consistentwith
thepresent
energycalibration.
ern energy
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of 3 mm diameter insteadof 2 mm and a di↵erent gain
the data. See text for details.
the data. See text for details.
Referencesof 0.8485 keV/channel.100
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the
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[1]
S.
et al., Nucl.
Meth.
A 602, 337 (2009).
B.AmanoLinearityof Instr.
a LaBrFig. 2(c), it turned out 0that the high-energy edge of the
3 (Ce) detectordata[2] gives
K. Horikawa, S. Miyamoto, S. Amano, and T.
data
gives
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full energy peak (therefore,
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Mochizuki, Nucl. Instr. Meth. A 618, 209(2010).
E [keV]is reproduced with excellent precision
although the peakEγ [keV]Using
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determinedby[3] A.theAndoet al.,
J. SynchrotronRad.
5, 342 (1998).
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E
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e =982.2(c)e, E[5] G. Audi, A.H. Wapstra and C. Thibault, Nucl. Phys. A
6000produced with a CO2 laser in comparison
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fit
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0540
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E [keV]changedthe-rayenergyby⇠
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[6]. StatistiStatisticallysignificant
eventswere
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cally significant events were observed above 667 MeV
MeV folfolFIG. 2. (Color online) (a) Monte Carlo simulation (dotted
FIG. 2. (Color online) (a) Monte Carlo simulation (dotted
lowed
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2000
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data at Een =850 MeV.

er

NEXAFS Study on Hyperthermal Atomic Oxygen Beam
Irradiation Effect on the Ti-containing DLC Film
Kazuhiro KANDA1, Kengo KIDENA1, Kazuhiro FUKUDA1, Ryo IMAI1, Masahito NIIBE1,
Synya FUJIMOTO2, Kumiko YOKOTA2, Masahito TAGAWA2
1
Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Japan,
2
Faculty of Engineering, Kobe University, Japan
Abstract
Surface structural changes of Ti-doped diamond-like carbon (Ti-DLC) film exposed to a hyperthermal atomic
oxygen beam were investigated using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy usingsynchrotron radiation. The spectral shape of the C K NEXAFS spectrum of as-deposited Ti-DLC film resembled
that of DLC film. After exposure to atomic oxygen, the spectrum resembled that of TiC powder. On the other
hand, the spectral shape in the Ti L NEXAFS spectrum of as-deposited Ti-DLC film resembled that of TiC
powder and became similar to that of TiO2 powder after exposure to atomic oxygen. These changes are
ascribable to the desorption of C atoms as CO and/or CO2 from Ti-DLC film due to the irradiation of atomic
oxygen beam.
Introduction
Diamond-like carbon (DLC) films were expected to be used as lubrication materials in space, where oil
cannot be used, because they exhibit excellent friction properties both in a vacuum and in air. One of the mostimportant concerns is the reliability of DLC films as a lubricating material in an extreme space environment(temperature, soft X-ray, radiation of atomic oxygen, and their synergistic conditions). The most important factor
in causing deterioration of the material in low Earth orbit (LEO), where artificial satellites and spacecraft are
positioned, is atomic oxygen exposure. In this orbit, artificial satellites and spacecraft are exposed to atomic
oxygen with a translation energy of 5 eV. In our previous study, we investigated the effects of atomic oxygen
exposure with an impinging energy of 5 eV on the surface chemistry and structure of DLC film surfaces by using
an atomic oxygen beam source [1]. A departure of hydrogen from DLC films and structural change of carbon
atom in the surface layer of a hydrogenated DLC film were verified during hyperthermal atomic oxygen
exposure.
Recently, the development of functional DLC films advanced due to the incorporation of other elements,
such as N, Si, F, and metal content, into DLC films to enhance their electrical, optical, and mechanical properties.
In particular, Ti-doped DLC films have been widely investigated due to their thermal stability. In the present
study, we investigated the effect of atomic oxygen exposure with an impinging energy of 5 eV on the surface
chemistry and structure of Ti-DLC films by measuring the near-edge X-ray absorption fine structure (NEXAFS)
spectra.
Experimental methods
The Ti-containing hydrogenated DLC (Ti-DLC) films used in this study are commercially available. The
films were deposited at 200 nm thickness on Si wafers by using an amplitude modulated RF plasma-enhanced
chemical vapor deposition (CVD) method. The hydrogen content of these films were estimated to be greater than
40 at.% using the combination of Rutherford backscattering spectrometry (RBS) and elastic recoil detection
analysis (ERDA) of DLC films by using the same synthesis method.
The exposure of an atomic oxygen beam into the Ti-DLC films was done using a laser detonation-type
beam apparatus located at the Kobe Univ. The translational energy of atomic oxygen was estimated to be 5.46
eV by using a time-of-flight (TOF) measurement system consisting of a quadrupole mass spectrometer with ascintillation detector and a multichannel scalar. The typical atomic oxygen flux at the sample position (46 cm
from the nozzle) was estimated to be 3.51×1015 atoms cm−2 s−1 by using a Ag-coated quartz crystal microbalance(QCM). In the present study, four sheets of Ti-DLC film were exposed to an atomic oxygen beam corresponding
to the fluences of 2.74×1019, 5.47×1019, 8.3×1019, and 1.85×1020 atoms cm−2, respectively. All exposure
experiments were carried out at room temperature.
The NEXAFS measurements were carried out on beamline 09A (BL09A). Undulator light dispersed by ainvalid spacing planer-grating monochromator was irradiated on the sample film at 54.7° (magic angle) withrespect to the surface normal of the samples. The NEXAFS spectra were measured in the total electron yieldmode. The measured energy range of the C K edge absorption and Ti L edge absorption were 275−330 eV and
450−500 eV, respectively.

33

Results and Discussion
Figure 1 shows the C K-edge NEXAFS spectra of a Ti-DLC film exposed to by an atomic oxygen beam withthat of a Ti-DLC film before exposure. The spectral features of the C K NEXAFS spectrum of the Ti-DLC film
before exposure resembled that of the DLC film. By the exposure to an atomic oxygen beam, the spectralfeatures of the C K NEXAFS spectrum of the Ti-DLC film noticeably changed. 1) A sharp peak was observed at
289 eV due to the increase in intensity at which a peak was observed as a small shoulder peak in the spectrum of
the Ti-DLC film before exposure. 2) The intensity of the peak at 285.4 eV decreased. This decrease indicates thatthe sp2 component decreased in the Ti-DLC film. The spectral features of the Ti-DLC film after exposure toatomic oxygen beam resembled that of TiC powder. In addition, the peak at 289 eV was assignable to the 1s→σ*transition originating from the C atoms neighboring the Ti atoms.
Figure 2 shows the Ti L-edge NEXAFS spectra of the Ti-DLC exposed to an atomic oxygen beam with that of
the Ti-DLC film before exposure. The spectral features of the Ti L NEXAFS spectrum of the Ti-DLC film before
exposure resembled that of TiC powder. After exposure to an atomic oxygen beam, the spectral features of the
Ti-DLC films changed and became similar to those of TiO2 powder.
From these results, the changes in the local structure of the Ti-DLC film due to exposure to an atomic oxygen
beam are summarized as follows: 1) In the as-deposited Ti-DLC films, almost all the C atoms were bonded toeach other with single bonding and double bonding at a certain ratio. Most of the Ti atoms bonded to the C atoms.
2) After exposure to an atomic oxygen beam, most of the C atoms bonded to Ti atoms and most of the Ti atoms
bonded to the O atoms. These changes are ascribable to the desorption of C atoms from Ti-DLC films due to theirradiation of the atomic oxygen beam. The C atoms were desorbed from the films as gas species (CO and/or
CO2). On the other hand, oxidized Ti (TiOx) was not desorbed from the Ti-DLC films as a gas species. Therefore,
the Ti/C ratio on the surface of the Ti-DLC films increased due to the irradiation of the atomic oxygen beam. As
the result, residual C atoms bonded to the Ti atoms. The sp2/(sp2+sp3) ratio of C atoms in the Ti-DLC films
exponentially decreased because the C-Ti bonding could not form double bonding. The discrepancy a theprevious work on DLC film [1] is ascribable to Ti-DLC films containing Ti atoms, which were not desorbed
from the film even if they were oxidized due to the irradiation of an atomic oxygen beam.

σ*
π*

TiC
1.85×10atoms/cm

2

8.3×10 19 atoms/cm 2
5.47×1019

atoms/cm 2

2.74×1019 atoms/cm 20 atoms/cm 2

19

Normalized absorption [a.u.]

Normalized absorption [a.u.]

TiO2
20

18.5×10 atoms/cm

2

19

8.3×10 atoms/cm 2
5.47×1019atoms/cm 2192.74×10 atoms/cm

20 atoms/cm 2

DLC

TiC
270 280 290 300 310 320 330 340
Photon energy [eV]Fig.1 C K-edge NEXAFS spectra of commercial
DLC film and Ti-DLC films before and after
exposure to atomic oxygen beam and TiC powder

450

460

470
480
490
Photon energy [eV]500

Fig.2 Ti L-edge NEXAFS spectra of TiC powder,
Ti-DLC films before and after exposure to atomic
oxygen, and TiO2 powder.

References
1) K. Yokota, M. Tagawa, A. Kitamura, K. Matsumoto, A. Yoshigoe, Y. Teraoka, Appl. Surf. Sci. 255 (2009)6710.
2) M. Tagawa, K. Yokota, A. Kitamura, K. Matsumoto, A. Yoshigoe, Y. Teraoka, K. Kanda, M. Niibe, Applied
Surface Science 256 (2010) 7678-7683.

34

Soft X-ray Irradiation Effect on Highly HydrogenatedDiamond-like Carbon Films
1

Ryo IMAI1, Makoto OKADA1, Shinji MATSUI1, Tsuneo SUZUKI2, Kazuhiro KANDA1
Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Japan,
2
Enegy-Density Research Institute, Nagaoka University of Technology, Japan

Abstract
Surface and bulk properties’ changes of a hydrogenated Diamond-like carbon (H-DLC) film
exposed to synchrotron radiation (SR) in the soft X-ray region were investigated by an atomic
force microscope (AFM) and a combination of Rutherford Backscattering Spectroscopy (RBS) andElastic Recoil Detection Analysis (ERDA) techniques. The surface of H-DLC films became flatand the hydrogen content of H-DLC films decreased with increasing SR dose.
Introduction
Diamond-like carbon (DLC) films have excellent properties including high hardness, a low friction
coefficient, high abrasion quality, a gas barrier, chemical inertness, and surface lubrication and are therefore
being utilized as coating materials on automobile parts, hard disks, artificial blood vessels, edged tools, andfood containers. Film-forming methods affect the properties of DLC films differently, and thus a wide varietyof DLC films have been developed. DLC films are expected to be used in outer space as a lubrication
substitution for oil, which cannot be used in space because it disappears in vacuums [1-2].
DLC films are generally known to be durable against X-ray exposure [3]. However, it has recently beenreported that soft X-ray exposure on highly hydrogenated DLC (H-DLC) films leads to desorption ofhydrogen and an increase in film density and refractive index [4-5]. A theoretical calculation has suggested
that this hydrogen desorption could be associated with a structural change of DLC films [6]. Clarification of
the effect of soft X-ray exposure on DLC films is necessary to ensure that DLC films can be used in outerspace safely.
In this study, we investigated the modification processes by soft X-ray exposure on H-DLC films.
Specifically the SR dose dependence of surface roughness (Ra), and hydrogen content was investigated. The
elementary composition analysis was performed using a combination of Rutherford Backscattering
Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) techniques. The surface roughness wasmeasured using an atomic force microscope (AFM).
Experiments
200-nm-thick H-DLC films were deposited on Si wafers by using an amplitude-modulated RF
plasma-enhanced CVD method. This method enables the deposition of DLC films containing a lot ofhydrogen. The SR irradiation of the H-DLC films was carried out at BL06 of the NewSUBARU synchrotron
facility at the University of Hyogo, Japan. The SR at the BL06 sample stage had a continuous spectrum fromIR to soft X-rays, lower than 1 keV. This includes 300 eV, which is the ionization energy of a carbon K edge.
As a result, the K-shell electrons of the C atoms could be excited by the SR at BL06. During this experiment,
the electron energy of the NewSUBARU ring was 1.0 GeV. The BL06 sample stage was room temperatureand the pressure in the chamber was the order of 10-5 Pa. An SR dose [mA･h] is derived from the product of
the ring current [mA] and exposure time [h]. The exposure on the H-DLC films was carried out over SR
doses ranging from 0 to 3000 mA･h.
Results and discussion
The hydrogen content of H-DLC films was quantitatively determined by RBS/ERDA. The measurements
were performed using an electrostatic accelerator (Nissin High Voltage, NT-1700HS) located at the Extreme
Energy-Density Research Institute, Nagaoka University of Technology, Japan. He + ions accelerated to 2.5
MeV using a tandem Pelletron accelerator were used as the incident beam, whose angle with respect to thesurface normal was 72. The measurement error of this apparatus is 1%.
Figure 1 shows the SR dose dependence of the hydrogen content of H-DLC films. The hydrogen content
of the unirradiated H-DLC films was 50 %. After SR exposure, the hydrogen content drastically decreasedin the range of 0200 mA･h, eventually becoming 30 % at 200 mA･h. Above 200 mA･h, the hydrogencontent slowly decreased and consequently became 20 %. This result shows that the SR exposure on
H-DLC films leads to hydrogen desorption. However, hydrogen of 20% in H-DLC films had no influence
due to SR exposure. This indicates that hydrogen atoms exist at different chemical environments in H-DLC
films: where hydrogen emitted or not emitted from films by the exposure to soft X-rays. It has previously
been found that the structure of H-DLC films varied to that of typical DLC films whose hydrogen content is35

2030 % by the exposure to soft X-rays [5].
The surface roughness of the H-DLC films were measured by using a tapping method with AFM
apparatus (SII nanotechnology E-sweep/nanoNavi Station); the determining area was 1000 × 1000 nm. SR
dose dependence of Ra estimated by the measurements of AFM, are shown in Fig. 2. The Ra of theunirradiated H-DLC films was 0.29 nm, which was the largest. The Ra of H-DLC films with even smallest
SR dose (10 mA・h) rapidly decreased compared to the unirradiated one. In addition, Ra remained
approximately constant at 0.18 nm in regions above 100 mA･h. These results show that SR exposure on
H-DLC films led to a decrease of Ra, and it also flattened the surface of the H-DLC films. In terms of thehydrogen content, the change was observed in 0200 mA･h. In contrast, the process of flattening decreased
at a lower SR dose. Therefore, the process of surface flattening differs from that of hydrogen desorption.
The modification of H-DLC films by the SR exposure includes hydrogen desorption and surface
flattening. Immediately after the SR exposure, the surface becomes flat due to desorption from the salient. Up
to 200 mA･h, the hydrogen content of the H-DLC films was 30 %.

0.5
0.4

40
Ra [nm]H/(C+H) [%]

50

30
20

0.2
0.1

10
0

0.3

0

0

1000
2000
SR dose [mA・h]

3000

Fig. 1. SR dose dependence of hydrogencontent of H-DLC films.
◯ and ● represent unirradiated andirradiated, respectively.

0

1000
2000
SR dose [mA・h]

3000

Fig. 2. SR dose dependence of surface
roughness of H-DLC films.
◯ and ● represent unirradiated andirradiated, respectively.

Conclusions
Soft X-ray irradiation effect on the surface and material properties of highly hydrogenated Diamond-likecarbon thin films was investigated using an atomic force microscope (AFM) and a combination of Rutherford
Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) techniques. The
hydrogen content of H-DLC films decreased from 50 % to 20 % by the SR exposure on films. Hydrogen
desorption was not observed at higher doses. In the range of 0200 mA･h, hydrogen content decreased. In
contrast, the surface roughness (Ra) of the H-DLC films decreased at lower SR doses compared withhydrogen content, and the surface of the H-DLC films became flat. We found that the modification processesof H-DLC films by SR exposure include hydrogen desorption and flattening on the surface.

References[1] C. Donnet et al., Tribology of Diamond-like Carbon, Springer (2008).
[2] C. Donnet et al., Surf. Coat. Technol. 68-69 (1994) 626.
[3] H. Kyuragi et al., Appl. Phys. Lett. 50 (1987) 1254.
[4] K. Kanda et al., Jpn. J. Appl. Phys. 50 (2011) 055801.
[5] H. Matsuura et al., SEI Tech. Rev. 171 (2007) 36 [in Japanese][6] Y. Miura et al., J. Appl. Phys. 93 (2003) 3395.

36

Low-Temperature Activation of Boron in Si wafer
by Soft X-ray Irradiation
Akira Heya1, Takuto Fukuoka1, Naoto Matsuo1, Kazuhiro Kanda2, and Takashi Noguchi3
1

University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
Phone: +81-79-267-4909 E-mail: heya@eng.u-hyogo.ac.jp
2
LASTI, University of Hyogo, 3-1-2 Koto, Kamigori, Hyogo 678-1205, Japan
3
University of the Ryukyus 1, Senbaru, Nishihara, Okinawa, 903-0213, Japan
Abstract
Novel activation method of B dopant using a soft X-ray undulator was investigated. The activationenergy of B activation by soft X-ray irradiation was lower than that of B activation by anannealing. As the irradiated photon energy closed with the core level of Si 2p, the activation ratio
increased. This related to the enhancement of electron excitation as a base on Felmi golden rule. At
low temperature, the B activation occurred by the atomic migration of Si atoms due to Coulomb
force via the electron excitation.
Introduction
Fabrication method of an ultra-shallow junction lower than 10 nm is required. We proposed a novel
activation method of B dopant at low temperature by using a soft X-ray undulator [1]. The photon energy
dependence of sheet resistance was investigated. In addition, the mechanism of soft X-ray activation was
discussed in comparison with a conventional thermal activation.
Exprimental
B ions were implanted to Si (100) wafer (n-type, 8-12 Ωcm) with an energy of 5 keV and a dose quantity of
2×1015 cm-2. The irradiation of soft X-ray was carried out at BL07A of NewSUBARU[1]. The photon energy
was changed from 50 to 250 eV, with the dose quantity of 50 mA h. In addition, to reduce the sample
temperature, the storage-ring current decreased from 250 to 50 mA. The gas pressure during irradiation was
6×10-5 Pa. The surface temperature of Si substrate during soft X-ray irradiation was measured by thermocouple
and via a ZnSe window by a thermo-viewer. For the comparison, the annealing in N2 atmosphere was carried out
in the range of 100 to 1000C.
The sheet resistance was measured by a four-point probe method at room temperature. The activation ratio
is given by Irvin curve and dopant dose quantity. Activation energy of B activation (Ea) was estimated by
Arrhenius plot of activation ratio.
Results and discussion
The sheet resistance and the temperature of Si wafer as a function of photon energy are shown in Fig. 1. The
temperature at the photon energy of 100 eV, which corresponds to the energy level of Si 2p core-electron (99.8eV), shows the highest value. The Si 2p core-electrons of Si atom are excited by soft X-ray irradiation and theyrelax resulting in a temperature increase of Si wafer. The activation was enhanced at 100 eV. According toFelumi golden role, the electron excitation is enhanced by closing to energy of core level. It is found that the
sheet resistance after soft X-ray irradiation strongly depended on the irradiated photon energy.
As the storage ring current decreased, the sample temperature decreased to 110C and the sheet resistance
was increased to 3.1 kΩ/□ (Fig. 2). The sheet resistance of annealed sample at 100C was 8.0 kΩ/□. It shows thatthe activation was enhanced by the electron excitation during the soft X-ray irradiation.
The relationship between the activation ratio and the reciprocal absolute temperature are shown in Fig. 3. The
sheet resistance of soft X-ray irradiated Si was lower than that of annealed Si below 400C. The Ea for the soft
X-ray activation was smaller than that for the annealing. The discrepancy of E a between the soft X-ray
irradiation and annealing indicates that the soft X-ray activation occurred by not only the thermal effect but also
the excitation of the core electrons followed by the atomic migration.
The activation mechanism of B by soft X-ray irradiation is considered as follows (Fig. 4). The activation byannealing generally occurs by movement of dopant atoms to lattice sites of Si. This process corresponds to the
Arrhenius plot for thermal annealing in high temperature range. The soft X-ray irradiation enhances the atomic

37

migration via excitation of Si2p core-electrons of Si. During the recovery of crystallinity in amorphizated Si
surface by atomic migration via electron excitation, B atom can shift to the lattice site of Si atom. Because thesize of B atoms is smaller than that of Si atom, the B activation is influenced by atomic migration of Si such as“knock-on” effect.
Conclusions
1) The activation of B dopant occurs at 110C, although the activation ratio shows small value of
6.2×10-3. The B activation ratio of Si wafer subjected to photon with an energy of Si2p and B1s were
1.8×10-2 and 5.7×10-3, respectively. Because the size of B atoms is smaller than that of Si atom, theenhancement of Si migration by soft X-ray irradiation triggers the movement of B atoms.
2) The B activation energy for the soft X-ray irradiation was smaller than that for the annealing. The soft
X-ray activation occurred by not only the thermal effect but also the excitation of the core electrons followedby the atomic migration.
References[1] A. Heya, K. Kanda, K. Toko, T. Sadoh, S. Amano, N. Matsuo, S. Miyamoto, M. Miyao, and T. Mochizuki: Thin Solid
Films 534 (2013) 334.

Fig. 1. Sheet resistance (closed symbol) and temperature of
Si wafer (open symbol) as a function of photon energy ofsoft X-ray. The insert shows the sheet resistance of Si wafer
for the photon energy from 90 to 115eV.

Fig. 3. Relationship between the activation ratio andreciprocal absolute temperature. Activation energy of
B dopant activation was estimated from the slope. The
Ea for the soft X-ray activation (0.06 and 0.09 eV) was
smaller than that for the annealing (0.16 eV).

Fig. 4. Schematic diagram of mechanism of
low-temperature activation by soft X-ray irradiation.
The soft X-ray irradiation enhances the atomic
migration via excitation of Si2p core-electron. During
the recovery of crystallinity in amorphizated Si surface
by the atomic migration via the electron excitation, B
atom can shift to the lattice site of Si atom.

Fig. 2. Sheet resistance and sample temperature as afunction of photon flux density (storage-ring current) at
photon energy of 115 eV. The B activation occurs at 110C,
although the activation ratio shows small value of 6.2×10-3.

38

Surface Modification in Silica-Based Films
by Undurator Radiation
K. Moriwaki, S.Takezawa, Graduate School of Eng./ Kobe Univ.,
K.Kanda, and S.Matsui, LASTI/Univ. Hyogo

Abstract
Undulator radiation (UR) by the NewSUBARU is used to modify the surface in pure silica andGeO2-doped silica films for optical waveguide devices. Irradiated films are found to show
reduction for both SiO2 and GeO2 bonds by analyzing XPS (X-ray Photoelectron Spectroscopy)
results. The surface reduction results generating Si-Si bonds show a clear peak-energy-dependenceof UR, in which there is a threshold energy near the L3 absorption-edge for Si. The surface
reduction layer for Si-Si bonds is found to be very thin less than 1.5nm, while that for Ge-Ge
bonds is less than 40nm.
Introduction
We use synchrotron radiation (SR) and undulator radiation (UR) for photo-induced refractive-index
modifications in silica-based glasses for optical waveguide devices1,2). Our main objectives are to induce
large refractive-index changes more effectively using SR or UR without a spectrometer, and to investigate
their origins depending on wavelengths of SR or UR spectra. Especially, UR would be a very useful tool forthe materials modifications, because it can select a useful wavelength and it has very high intensity. For thosereasons we mainly use UR for the materials modifications. In this report, we investigated themodification effects on the surface of SiO2 films or GeO2 doped SiO2 films irradiated with UR.
XPS was mainly used for the characterizations.

Intensity(arb.unit)

Experiments and Results
Experimental conditions are almost the same as in the previous experiments1,2). UR (from the
NewSUBARU BL-7A) was mainly used to investigate irradiation-wavelength effects. SR (from the
NewSUBARU BL6) was also irradiated on samples directly without a spectrometer. The electron energy of
the SR was 1GeV. The UR peak energy in the first order was controlled from 20 to 120 eV. The samples were
thermally grown SiO2 films (0.5 or 1 m thickness) on Si substrates and GeO2-doped SiO2 films (2 mthickness) fabricated by the FHD (Flame Hydrolysis Deposition) technique on Si substrates in thisexperiments. Relative refractive index difference for the GeO2-doped SiO2 films was 1.9%. XPS
measurements and the following RIE (Reactive Ion Etching) were used to investigate the surface reduction
effects and depth profiles for the modification.
It was shown in Fig.1 that Si-Si bonds weregenerated on the surface of thermally grown SiO2
Si4+
films, after irradiating UR with peak energy values
UR:20eV 1000mAh
UR:60eV 1000mAh
of 20, 60, and 80eV by measuring Si2P peaks in the
UR:80eV 1000mAh
XPS. On the other hand, after irradiating UR with
UR:100eV 1000mAh
UR:120eV 1000mAh
peak energy values of 100 and 120eV, Si-Si bonds
before irradiation
were not generated as shown in Fig.1. It may
suggest that the Si-Si bonds generations are
Si0
influenced by the L3 absorption at 99.2eV for Si.
The modified layer was very shallow, because thegenerated Si-Si bonds on the surface weredisappeared after etching the sample up to a depthof 1.5 nm as shown in Fig.2. The etched sample in
108 106 104 102 100 98
96
94
92
Fig.2 shows the same SiO2 bond peak without a
Binding
Energy(eV)
Si-Si bond peak as in the original ones. In GeO2
doped SiO2 films irradiated by UR, almost the same
FIG.1. Si2p peaks in the XPS spectra, before andtendency were found for the Si-Si bonds generation.
after irradiating UR with peak energy from 50 to
The depth profile was also the same as that in the
120 eV in pure SiO2 films. Si-Si bonds are
Fig.2
generated for the sample for peak energies less
As for the Ge3d peaks in GeO2 doped SiO2 films
after irradiating UR, the reduction layer with Ge-Ge
than 100eV. The UR dose was 1000mAh.
bonds was also found to be generated especially for

39

O2s
Ge0

40

35

30

25

108

106

104

102

100

98

96

94

92

Binding Energy(eV)FIG.2. Si2p peaks in the XPS spectra, before,
after irradiating UR with a peak energy of 60 eV
and after etching up to a depth of 1.5nm in SiO2
films. The generated Si-Si bonds are
disappeared after the etching as in the
non-irradiated sample. The UR dose was
1000mAh.

UR:50eV 1000mAh
UR:60eV 1000mAh
UR:80eV 1000mAh
UR:100eV 1000mAh
UR:120eV 1000mAh
before irradiation

UR:60eV 1000mAh
UR 10nm etching
UR 20nm etching
UR 30nm etching
UR 40nm etching
before irradiation

Intensity(arb.unit)

Intensity(arb.unit)

Ge4+

UR:60eV 1000mAh
UR 1.5nm etching
before irradiation

Intensity(arb.unit)

low peal-energy such as 50 or 60 eV as shown in
Fig.3. The Ge-Ge peak decreases gradually byincreasing the peak energy of UR. For a sample
irradiated with peak energy of 100 or 120eV, peaks
for Ge-Ge bonds are not seen in Fig.3, but this might
be caused by a weak intensity for the Ge3d peak ascompared to that for Si2p. The threshold energy is notclear for the Ge-Ge bonds generation comparing tothat for the Si-Si bonds, which may be caused by theabsence of clear absorption-edge for Ge around theirradiation energy range. After etching the sample, thereduction layer with Ge-Ge bonds was removed by 40
nm-deep etching. The Ge-Ge bonds layer is generated
deeper than that for the Si-Si bonds layer of 1.5nm,
which may be a cause of a penetration-depth
difference for the effective irradiation wavelength.
The surface reduction effects appeared in Fig.1 waschanged by other samples with different film
thickness. A sample with thinner film with the same
irradiation condition showed more intense peaks for
Si-Si bonds in the XPS. Sample temperature might be
the origin for the thickness dependence, because thesample temperature might be more than a few
hundreds of degrees during the irradiation.

40

20

35

30

25

20

Binding Energy(eV)Binding Energy(eV)FIG.4. Ge3d peaks in the XPS spectra, before,
after irradiating UR with a peak energy of 60 eV
and after etching up to a depth of 40nm in GeO2
doped SiO2 films. The generated Ge0 peaks are
disappeared gradually by increasing the etching
depth. After 40nm etching, Ge0 and Ge4+ peaks
are almost the same as that in the non-irradiatedone. The UR dose was 1000mAh.

FIG.3. Ge3d peaks in the XPS spectra, before
and after irradiating UR with a peak energy
from 50 to 120 eV in GeO2 doped SiO2 films.
Ge-Ge bonds are generated for the sample forpeak energies of 50 and 60eV. The peakintensity for the Ge-Ge bonds (Ge0) is gradually
decreased for peak energy from 80 to 120 eV,
The UR dose was 1000mAh.

Conclusions
UR irradiation effects are investigated for an application of silica-based materials to optical waveguidedevices. Although large refractive-index changes were obtained by SR and UR irradiation in silica-based
films in our previous report1), other modification effects such as the surface reduction shown here are also
important in the applications as an utilization tool and an obstacle for other applications. In our results, it isshown that the surface modification effects for Si and Ge bonds could be controlled by changing the peakenergy of UR. From those results, UR is expected to be a useful irradiation source for modifying materials
effectively and also controlling the modification effects as a desired way.
References[1] K.Moriwaki et al., LASTI Annual Report vol.10 (2008).
[2] K.Moriwaki et al., LASTI Annual Report vol.13 (2011).

40

Characterization BN Thin Film Deposited on Cemented
Carbide using Soft X-ray Absorption Spectroscopy
Masahito Niibe1, Takuya Kotaka1, Satoshi Jinguji2, Satoko Hori2, and Shozo Inoue2
LASTI 1 & Graduate School of Eng., 2 University of Hyogo
Abstract
Crystalline structure of BN thin film deposited on cemented carbide substrate by magnetron
sputtering technique was characterized using soft X-ray absorption spectroscopy (XAS). Boronand nitrogen K near edge X-ray absorption fine structures (NEXAFS) of the BN thin films were
measured with total electron yield (TEY) method and total fluorescence yield (TFY) method. The
film structure changed dramatically from t-BN phase to c-BN phase when film thickness increased
from 6.5 nm to 20 nm. The crystalline structure of the film deposited on the WC substrate with abias voltage of -90 V was still t-BN type. However, the structure changed to c-BN phase when thebias voltage increased to -130 V.
Introduction
As similar to carbon allotropic forms, boron nitride presents a polymorphism of hexagonal structure (h-BN)
having a hexagonal plane network; such as graphite, and cubic structure (c-BN) having a steric structure; such as
diamond. It is well known that h-BN is a relatively soft material. However, c-BN is known to be the second
hardest material after diamond. The preparation of c-BN thin film for a coating material onto cutting tools is
extensively studied. In cases of BN thin film fabrication by sputtering or ion plating depositions, h-BN structure
is preferentially formed because it is a stable phase at normal pressures. Stably-forming technology for c-BN
structured thin film was not confirmed as affairs.
Characterization of crystalline structure of BN thin film is indispensable to confirm the fabrication
technology. Near edge X-ray absorption fine structure (XANES) spectroscopy is an appropriate technique toidentify the crystal structure of BN thin film because the spectra of c-BN and h-BN are quite distinct and thebonding state on sp2 and sp3 can be observed in isolation. In this study, NEXAFS measurement at B-K and N-Kedge was carried out for the characterization of crystalline structure of BN thin film deposited on cemented
carbide (WC) as well as Si wafer by an RF magnetron sputtering technique.
Experiments
BN thin films were prepared on Si (100) and WC substrates by the RF magnetron sputtering system. The
substrate holder was electrically floated for applying a bias voltage and could be heated up to 600°C,
simultaneously. Ar+N2 mixed gas was used as working gas, and its pressure was 0.4 Pa. The DC bias waschanged from -80 to -130 V in this study. Atomic composition of the prepared sample was determined by an
Auger electron spectroscopy (AES).
B-K and N-K NEXAFS spectra of prepared samples were measured in the analyzing station of the beamline
BL9a at the NewSUBARU SR facility. The beamline monochromator was mounted with a plane varied-spacegrating with central groove density of 1200 l/mm, the energy resolution of which was about 0.2 eV near thephoton energy of 400 eV. The measurement was conducted with a total electron yield (TEY) method with sample
current mode and with a total fluorescence yield (TFY) method with measuring the amount of fluorescence by aphotodiode [1] for the same sample at the same position. It is well known that the TEY method can yield
information in a shallow region from the sample surface because of the small escape length of photo-generated
electrons of less than about 5nm [1, 2]. Meanwhile, the TFY method can yield information in a deeper region(bulk) of the sample of more than 100 nm [1] because of the much longer penetration depth of soft X-ray
photons.
Results and discussion
In order to clarify the growth process of BN films containing the c-BN phase, the films were deposited for 1,
2, 3, 5, and 30 min at 600°C and applied bias voltage of -90 V. Figures 1 and 2 show the B-K and N-K
absorption spectra of a prepared films, respectively. The thicknesses of those films were estimated to 6.5, 13, 20,
33, and 200 nm using the deposition rate. For the 6.5-nm-thick film, both B-K edge and N-K edge spectra have alarge π* resonance peaks at 192 eV for B-K and at 401 eV for N-K edges, respectively, which are caused fromsp2 bonding states like a graphite. As the thickness increases to 20 nm, the π* peak at 401 eV in N-K edge
spectra becomes a shoulder. The B-K edge spectrum for the 20-nm-thick film also shows that film has anc-BN-dominant strucrure in spite of the presence of the small π* peak. The NEXAFS spectra for the films withthe thicknesses of 33 nm and above are almost the same as the spectraum of the 20-nm-thick film. This meansthat the t-BN (or h-BN with sp2 bonding) underlayer thickness of the film deposited at 600°C was less than 20

41

nm and that the c-BN-dominant layer grew from an early stage of the deposition. It was also found from themeasurement of incident angle dependency that the t-BN underlayer had a preferential orientation of the c-axis
parallel to the film surface. The results also correspond well to the results of infrared absorption spectra
measured with FT-IR spectrometer [3].

Fig. 2 N-K XANES spectra of BN thin films withvarious film thicknesses prepared on Si wafer at 600℃.

Fig. 1 B-K NEXAFS spectra of BN thin films with various
film thicknesses prepared on Si wafer at 600℃.

After the structural investigation on the Si substrate, we deposited BN films onto the Si wafer and thecemented carbide (WC) substrates at the same time with substrate temperature of 600°C. At the negative bias
voltage of -90 V, the crystalline structure of the film deposited on the WC substrate was still t-BN phase as
shown in Fig. 3, though the structure of film simultaneously deposited on the Si wafer was c-BN phase. N-K
NEXAFS spectra at different angles of incidence of 90° and 45° for the prepared BN film are shown in Fig. 3 for
TEY and TFY methods. Although, the π* resonance peak measured by TFY method (bulk) shows a small
dependency of incident angle, the angular dependency is very large for the spectra obtained by TEY method(srrface). When the negative bias voltage increased to -130 V, the NEXAFS spectrum on WC substrate changed
dramatically to c-BN phase as shown in Fig. 4.
It is difficult to evaluate the crystalline structure of BN film deposited on WC substrate by transmission type
FT-IR spectroscopy. Therefore, the results obtained in this study suggests the effectiveness of X-ray absorption(NEXAFS) spectroscopy for evaluation of crystalline structure of BN thin films deposited on WC substrates.
BN film on hard metal_N-K TEY, TFY
58

4

Absorption intensity [a.u.]

Absorption intensity [a.u.]

BN#34 on WC_N-K TEY,TFY10

TFY 45°

6

TFY 90°4
TEY 45°2

TEY 90°3

TFY 90°

2

1
TEY 90°

0
390

400

410

420

0
390

430

Photon energy [eV]

400

410

420

430

Photon energy [eV]Fig. 3 N-K NEXAFSS spectra of the BN thin film
prepared on WC substrate with a bias voltage of -90 V.

Fig. 4 N-K NEXAFS spectra of the BN thin film preparedon WC substrate with a bias voltage of -130 V.

References[1] M.Niibe T. Kotaka, T. Mitamura: J. Phys. Conf. Ser., 425, 132008, (2013).
[2] J. Stohr, “NEXAFS Spectroscopy” Springer, Berlin (2003).
[3] S. Hori, M. Niibe, T. Kotaka, S. Inoue et al., Jpn. J. Appl. Phys., 52, 045602 (2013).

42

Spectral Recovery of Etching Damage by Soft X-ray
Irradiation Observed in XAS spectra of TiO2 Thin Film
Keiji Sano1, Masahito Niibe1, Takuya Kotaka1,
Retsuo Kawakami2, Kikuo Tominaga2, Yoshitaka Nakano3(Univ. Hyogo 1, Univ. Tokushima 2, Chubu Univ. 3)
Abstract
We analyzed TiO2 thin films etched with capacitively coupled plasma etching apparatus by nearedge X-ray absorption fine structure（NEXAFS）method. As a result, spectral change due todisordering of the crystalline structure was observed by TFY method in the sample treated withhigher gas pressure. We also found that Ti-L spectra of etched sample was recovered to as-grownlike by irradiation with soft X-rays (496 eV) for 10 min. This recovery occurred not only on theirradiation point of soft X-rays but also on the point 2 mm or more away. Furthermore, it was
found that the spectral recovery can also be observed for the surface irradiated with ultraviolet(UV) light instead of soft X-rays.
Introduction
TiO2 is expected to apply as MOS gate oxide film because of its high dielectric constant. To use TiO2 as
MOS gate film, it has to be processed by etching. However, there are few reports about the effect of etchingdamage to TiO2 thin films by etching process. Therefore, we analyzed the effect of etching damage to TiO2
samples by NEXAFS method. As it happens, we found the phenomenon in the analyzing process that disordered
NEXAFS spectra of the etched film recovered to as-grown like by irradiation with soft X-rays.
The purpose of this study is the elucidation of the phenomenon that NEXAFS spectra of etched TiO2 thinfilm were recovered by soft X-ray irradiation. We investigated the condition of the etching damage to recover.
For example, recovery of the spectra is studied for irradiation condition, light source, and irradiation position.
Experiments
TiO2 thin films were deposited on a glass substrate（Corning 1737）by facing cathodes DC magnetron
sputtering system. We used capacitively coupled plasma (CCP) etching apparatus (Tokushima Univ.) to etch thesamples. The etching gas was N2 and its pressure and etching time were varied from 10 to 100 mTorr and 5 to
200 minutes, respectively. These samples were analyzed by NEXAFS method conducted at BL09A in the
NewSUBARU synchrotron radiation facility[1]. The measurements were carried out with total fluorescence yield(TFY) method (bulk sensitive) and total electron yield (TEY) method (surface sensitive) at the Ti-L2,3 edges (443
~ 496 eV)[2]. NEXAFS method can obtain the information of chemical state or local structure around the element
selectively by measuring an absorption edge of any element in the sample in non-destructive.
Results
As shown in Fig.1 (a), the spectra measured by TFY method was changed that the peak near 467 eV became
lower with increasing the etching gas pressure. However, as shown in Fig.1 (b), there was little change due toincrease of the gas pressure in the spectra by TEY method. Therefore, we got a very strange result that theetching damage of the sample surface was small but the damage at the sample inside was larger.
Continuing the measurement in order to investigate the cause, we found that the spectra of the etched sample
were recovered to as-grown like by soft X-ray irradiation. Fig.2 shows the recovery process of the NEXAFS
spectra by soft X-ray irradiation measured with TFY method. The etching gas pressure of the sample was 100
mTorr, and the etching time was 60 minutes. The spectrum of etched sample became as-grown like by soft X-ray
irradiation (496 eV, tens of mW/cm2) for 30 minutes. After the irradiation, the spectra of recovered samples werereturned to disordered shape by exposure to air, and then measured again after 21 days later. After returning todisordered shape by air exposure, the sample spectrum changed to as-grown like again by re-irradiation with soft
X-rays for 10 minutes.
The bonding orbital around the Ti atoms should be disturbed by generation of oxygen vacancies. The spectra
should be disturbed by disarray of crystalline structure. Therefore, it was considered that the spectra wererecovered by supplement of the defective part. Since the spectral recovery by soft X-ray irradiation returned tothat of after etching by exposure to the air, we considered that the spectrum recovered apparently by electrons
which are from the electron-hole pairs generated by light irradiation and are trapped at the oxygen vacancies.
Etched Sample was irradiated with soft X-rays for 25 minutes at the center position of the sample in order tofind out whether NEXAFS spectrum was recovered as spatially distributed. After irradiation, the sample wasmeasured at the position separated from 2 mm above and below the irradiation center. soft X-rays were notirradiated at the position separated 2 mm from the center because the beam size of irradiated soft X-rays in

43BL09A is 0.8 mmH × 0.3 mmV. However, the spectrum was recovered as-grown like not only at the center
position of the sample but also the position separated 2 mm above and below from the center. We consider thatrecovery of spectrum was observed at the position outside of the irradiation due to the diffusion of generated
excitons to the periphery of the irradiation position as free excitons.
If the fact of spectral recovery is caused by excitons generated by soft X-ray irradiation, it is considered thatthe spectra should be recovered by UV irradiation instead of the soft X-rays, the energy of which is above theband gap energy of anatase TiO2 (3.2 eV). Therefore, we tried to irradiate UV light (3.4 eV, 49 mW/cm2) to theetched sample (CCP-N2, 100 mTorr , 60 min) in vacuum. Fig.3 shows the recovery process of the NEXAFS
spectra by UV irradiation measured with TFY method. The spectrum of etched sample was recovered toas-grown like by UV irradiation. From the results above, it was considered that the spectral recovery of theetched sample should be apparent recovery due to the electrons generated by soft X-ray irradiation and trappedin the oxygen vacancies.
3.0

3.0

CCP N 2 60min

TFY

2.5

100 mTorr

Absorption Intensity [a.u.]

Absorption Intensity [a.u.]

2.5
2.0
1.5

50 mTorr

1.0

10 mTorr

CCP N 2 60min

TEY

0.5

100 mTorr
2.0
1.5

50 mTorr

1.0

10 mTorr

0.5

as-grown

as-grown

0.0

0.0
450

460

470

480

490

450

Photon Energy [eV]

460

470

480

490

Photon Energy [eV]Fig.1 Ti-L2,3 NEXAFS spectra of etched TiO2 thin films(a): TFY method and (b): TEY method.

2.5

CCP N 2
100mTorr 60min

TFY

Absorption Intensity [a.u.]

3.5

Re-irradiation for 10 min

3
2.5

After 21 days

2

irradiation for 30 min(496 eV)

1.5
After etching

1

CCP N 2TFY
Absorption Intensity [a.u.]

4

100mTorr 60min

2

UV irradiation for 10 min
in vacuum
1.5
After etching1

0.5
as-grown

0.5
as-grown

0

0
450

460

470

480

450

490

Photon Energy [eV]

Fig.2

460

470

480

490

Photon Energy [eV]

Recovery of Etching Damage
by Soft X-ray Irradiation.

Fig.3

References[1] M.Niibe et al.: AIP Conf. Proc. No.705 (AIP, New York, 2004), p.576[2] T.Kotaka and M.Niibe: Adv. X-ray Chem. Analysis, 43 (2012) 175.

44

Recovery of Etching Damage
by UV Irradiation.

Modification of Electronic States of Multi-layer Graphenes by
Ion Irradiation
S. Honda1,7, A. Tsukagoshi1,7, R. Osugi1,7, M. Niibe2, and M. Terasawa2,71
Univ. of Hyogo, 2LASTI Univ. of Hyogo
R. Hirase3, H. Yoshioka3, and H. Izumi3
3
Hyogo Pref. Inst. of Tech.
K.-Y. Lee4
4
National Taiwan Univ. of Sci. and Tech.
K. Niwase55
Hyogo Univ. of Teacher Education
E. Taguchi6
6
Research Center for Ultra-High Voltage Electron Microscopy, Osaka Univ.
M. Oura7
7
RIKEN SPring-8 Center

Abstract
Low energy Ar ions (0.5 - 2 keV) were irradiated to multi-layer graphene films and the local electronic states
were investigated by x-ray absorption spectroscopy (XAS). XAS analysis indicated that the number of
sp2-hybridized carbon (sp2-C) atoms decreased after ion irradiation. At the same time, sp3-hybridized carbon(sp3-C) atoms were suggested to be formed in the multi-layer graphenes.

Introduction
Graphenes [1] have been attracting
tremendous attention as new semiconductors
because of their intriguing properties, such as theextraordinarily high room-temperature carrier
mobility, high thermal conductivity and highYoung's modulus. These properties of graphenes
can be employed in numerous potential
applications such as transparent conductors andquantum devices. On the other hand, the controlof electrical and optical properties is essential torealize graphene devices. Irradiation of graphenes
with energetic particles is thought to enable us tocontrol their properties and structure [2,3]. It has
been reported that the doping level of graphenes
can be also controlled by ion irradiation [4].
Several analytical techniques can be used tocharacterize irradiated graphenes. For example,
Raman spectroscopy [5–9], transmission electron
microscopy (TEM) [10], scanning tunnelingmicroscopy (STM) [11], and X-ray photoelectron
spectroscopy (XPS) [3] have been employed to
study the properties and structure of irradiatedgraphenes. Soft X-ray absorption spectroscopy(XAS), on the other hand, is a powerful tool since
it provides information on not only the local
electronic structure surrounding excited carbon
atoms, but also the orientation of the carbon π
bonds [12]. In this study, to modify the electronic
states of the multi-layer graphenes by theirradiation, we irradiated multi-layer graphenes
with low-energy Ar ions (0.5–2 keV), andinvestigated the local electronic states by XAS.

Experiments and Results
Multi-layer graphene films were synthesized
by thermal catalytic chemical vapor deposition.
Figure 1(a) shows a transmission electron
(a)

5 nm

(b)

Intensity (a.u.)

2D

2600

2650
2700
2750
Raman Shift (cm-1)

2800

Fig. 1. (a) Cross-sectional TEM image ofas-prepared multi-layer graphene films. (b) 2D
peak of Raman spectrum of as-prepared graphenefilms.

45

microscopy (TEM) image of as-preparedmulti-layer graphene films. The number and thetotal thickness of graphene layers were 6 andabout 2 nm, respectively. We employed a
Kaufman ion source (ULVAC-PHI MOD
04-370B) to irradiate the multi-layer graphenefilms at room temperature (RT) with Ar ions. The
incident energy ranged from 0.5 to 2 keV and thedose varied between 1×1013 and 1×1015 cm-2.
Micro-Raman spectra were taken with Ar ion
laser (514.5 nm) using a Raman spectroscope(JASCO, NRS-2100). Fig. 1(b) shows the 2D
peak of the Raman spectrum of the graphenefilms. It has been reported that the 2D peakchanges in shape, width, and position withincreasing number of graphene layers [13]. On thebasis of the previous assignment, the number ofgraphene layers is estimated to be 3–5. This result
is consistent with the results of TEM. The carbon
K-edge XAS measurement was performed using
BL09 of the 1.5 GeV synchrotron radiation source
NewSUBARU at the University of Hyogo [14].
The total electron yield method was used for themeasurement.
In order to explore local electronic states ofthe multi-layer graphene films, XAS was utilized
for the multi-layer graphene films irradiated under
different conditions. The spectra were measured
at different angles of incident soft X-rays to thesubstrate surface (α) and normalized to theirintensity at ∼320 eV. Fig. 2 is the XAS spectra ofgraphene films irradiated at an energy of 1 keV,taken at α=55°. The π∗ peak of 285 eV and σ∗peak of 292 eV were clearly observed. The sp2-C
atom generally exhibits both π∗ and σ∗ peaks,
whereas the sp3-C atom exhibits only the σ∗ peak[15]. It was found that the intensity of the peakdecreased with increasing ion fluence. This
indicates decreasing number of sp2-C atoms after
the ion irradiation. At the same time, an additional
shoulder at ∼289 eV is also recognized after theion irradiation, as shown by arrow in Fig. 2. Theenergy at the shoulder is close to that at the C-K
absorption edge for single-crystal diamond, andmay be related to the formation of sp3-C atoms inthe multi-layer graphene films [16]. With
increasing ion fluence, an additional peak at ∼287
eV was recognized in the XAS spectra, as shownby arrow in the Fig. 2. Additional peaks at ∼289
eV and ∼287 eV, which appeared similarly in theprevious study for the study for the damaging
stages of multiwalled carbon nanotube films [17],have been respectively assigned to relate to theformation of sp3-C and dislocation dipoles. The
dislocation dipoles possess fivefold and sevenfold
rings, thereby inducing the buckling and therotation of the hexagonal networks [18–20].

+

1 keV Ar

Intensity (a.u.)

1×1015 ions/cm2

1×1014 ions/cm2

π*

280

σ*

as-prepared

290

300
310
Energy (eV)320

Fig. 2. XAS spectra of multi-layer graphenefilms irradiated by 1 keV Ar ions at different
fluences.
References[1] K. S. Novoselov et al., Science 306, 666 (2004).
[2] A. V. Krasheninnikov and K. Nordlund, J. Appl.
Phys. 107 (2010) 071301.
[3] F. Banhart et al., ACS Nano 5 (2011) 26.
[4] H.-G. Jee et al., Phys. Rev. B 84 (2011) 075457.
[5] G. Compagnini et al., Carbon 47 (2009) 3201.
[6] J.-H. Chen et al., Phys. Rev. Lett. 102 (2009)
236805.
[7] Y.-B. Zhou et al., J. Chem. Phys. 133 (2010)
234703.
[8] J. J. Lopez et al., Appl. Phys. Lett. 107 (2010)
104326.
[9] S. Mathew et al., J. Appl. Phys. 110 (2011)084309.
[10] J. C. Meyer et al., Nano Lett. 8 (2008) 3582.
[11] L. Tapasztó et al., Phys. Rev. B 78 (2008)
233407.
[12] T. Hemraj-Benny et al., Small 2 (2006) 26.
[13] A. C. Ferrari et al., Phys. Rev. Lett. 97 (2006)
187401.
[14] M. Niibe et al., AIP Conf. Proc. 705 (2004) 576.
[15] J. Stöhr, NEXAFS Spectroscopy (Springer,
Heidelberg, 1992).
[16] F. L. Coffman et al., Appl. Phys. Lett. 69(1996) 568.
[17] S. Honda et al., Jpn. J. Appl. Phys. 51 (2012)
110202.
[18] K. Niwase, Philos. Mag. Lett. 82 (2002) 401.
[19] K. Niwase, Mater. Sci. Eng. A 400–401(2005) 101.
[20] K. Niwase, Int. J. Spectrosc. 2012 (2012) 1.

46

Fabrication of amino acid analysis chipusing SR direct dry etching of PTFE
H. Kido a, I. Okada b, H. Mita c, A. Yamaguchi a, and Y. Utsumi a
University of Hyogo, 3-1-2 Kouto, Kamigori, Ako, Hyogo, 678-1205, Japanb
Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japanc
Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi-ku, Fkuoka, 811-0295, Japana

Abstract
Polytetrafluoroethylene (PTFE) is very attractive material for various fields, because of its
chemical resistance and heat resistance, etc. But, micro fabrication of PTFE is very difficult fromits high stability. Therefore, PTFE has never been applied to micro fluidic device. However, it is
known that synchrotron radiation (SR) induces scission of polymer chain of PTFE. We have everbeen succeeded in the fabrication of PTFE micro fluidic chip using SR dry etching and thermal
compression bonding. As a next step, we have been engaged in the fabrication of PTFE micro
fluidic chip for amino acid derivatization process. PTFE is an ideal material for performing thederivatization process. Because, this process using some strong acid, and some processes such as
extraction and hydrolysis require high temperature heating operation. There is no precedent of theapplication of such complex micro structure made of PTFE to the device for chemical analysis.
Introduction
In Solar system bodies, Amino acids, which are biologically important organic compounds, have played a
key role in the chemistry that led to the origin of life on Earth. Precise analysis of the amino acid contained in
extraterrestrial samples is very important in the study of the origin of life. We recently have opportunities foranalyzing fresh extraterrestrial samples by collection of cosmic dust and sample return from asteroids, etc [1].
However, the amounts of the samples which can be used for analysis are limited because the samples are smallin amount. Therefore, amino acid analyses for the samples using a micro fluidic chip are required. In this study,
we develop the micro fluidic chip which can realize fluorescent derivatization required for optical isomer ratio
analysis of the amino acid included in the samples.
Experiments and Results
The sequence of analysis operations for the amino acid in the extraterrestrial samples includes extraction,
filtration, hydrolysis, and evaporative drying. Therefore, high chemical resistance and heat resistance are
required for the material of the chip. For this reason, we chose polytetrafluoroethylene (PTFE) as a chip material.
PTFE has very excellent chemical stability, and its heat resistance is far higher than those of plastic materials.
Although the PTFE has the high chemical stability, micro fabrication of PTFE is difficult because the small
modulus of elasticity is not suitable for normal mechanical processing. Up to now, micro fluidic device made ofPTFE has never been reported. It is known that synchrotron radiation (SR) induces scission of polymer chain of
PTFE [2 3]. Figure 1 shows the etching mechanism of SR direct dry etching of PTFE. We have been fabricated
PTFE microstructures by direct dry etching using SR [4]. The combination of PTFE microstructure using SR
dry etching process and compression bonding enables us to PTFE micro fluidic chemical analyzer. In previous
study, we fabricated simple micro fluidic chip which had only one micro channel.
In this study, we developed a novel micro fluidic device which had multiple micro channels and incorporated
a filter structure for filtration. Figure 2 shows the schematic diagram of fabricated amino acid analysis device.
This device consists of two chips, and the function of valve is performed by sliding of the upper chip. The microchannels are incorporated into the lower chip. The lower chip has four reservoirs for reagent such asderivatization reagent, and each reservoir can hold 10l. In addition, we disposed two reaction reservoirs for
extraction and derivatization into the lower chip. Extraction reservoir has micro filter for filtration of protein
contained in the sample on the downstream side of reservoir. We set the filter dimension to 50m squarebecause the size of extraterrestrial sample is assumed to be 100–200m in diameter. Derivatization reservoir
operates the hydrolysis of protein to amino acid and fluorescent derivatization. Heating operation in thederivatization reservoir is required in both sealed and open states. We realize both heating states in a single
reservoir by opening and closing the upper part of the reservoir using the slide mechanism. In addition, the filter
structure is incorporated in the derivatization reservoir for prevention of liquid leakage. For the function of thecapillary valve, we set the filter dimension to 50m square.
There is no precedent of the application of such complex micro structure made of PTFE to the device forchemical analysis. This study is very important for progress of science, technology and space development
because our device has the potential to perform the chemical analysis with laboratory level on the spot where
we are difficult to visit.

47

Figure 1. Etching mechanism of SR direct dry etching of PTFE: (a)drastic bond break in near surface, (b) bond break deep inside of thesubstrate and vaporizing from surface, (c) melting point shift andvaporizing from deep inside of the substrate, (d) penetrationof mask pattern.

Upper chip

Valve channel
Reagent reservoir
Compressed air inlet
Sample outlet

Filtration filter
Sample inlet

Extraction reservoir
Derivatization reservoir Lower chip

Micro filter (50m square)

Figure 2. Schematic diagram of amino acid analysis device.
References[1] D. E. Brownlee, P. Tsou, J. D. Anderson, M. S. Hanner, R. L. Newburn, Z. Sekanina, B. C. Clark, F.
Horz, M. E. Zolensky, J. Kissel, J. A. M. McDonnell, S. A. Sandford, A. J. Tuzzolino, JGR Planets, 108 (E10)(2003) 8111-8126.
[2] Y.Zhang, T.Katoh, M.Washio, H.Yamada, S.Hamada, Appl.Phys.Lett.67 (1995) 872-874.
[3] Yuichi Utsumi, Takefumi Kishimoto, Tadashi Hattori, Hirotsugu Hara, Jpn. J. Appl. Phys., 44,7B (2005)
5500-5504[4] Yoshiaki Ukita, Kazuhiro Kanda, Shinji Matsui, Mitsuyoshi Kishihara, Yuichi Utsumi, Microsyst
Technol 14 (2008) 1567-1572.

48

Powder Transport Direction Control Method by Using
Drive Frequency of Surface Acoustic Wave
Yasuto Arisue1, Yuya Matsui1, Tsunemasa Saiki2, Kazusuke Maenaka3, Akinobu Yamaguchi1
and ,Yuichi Utsumi1
1
Laboratory of Advanced Science and Technology for Industry, University of Hyogo,
3-1-2 Koto, Kamigori, Ako-gun, Hyogo, 678-1205, JAPAN
Phone: +81-791-58-0232, Fax: +81-791-58-0232,
2

Hyogo Prefectural Institute of Technology, Kobe, 654-0037, JAPANE-mail: pippikki@lasti.u-hyogo.ac.jpPleaseabstract
We propose a novel method for controlling the powder transport direction by drive frequency,
and demonstrate the validity of this method by experiments. In our experiments we could observe
several powder transports by specific combinations of inclination angles and drive frequencies.
Introduction
To integrate a lab-on-a-chip has been extensively studied. The surface acoustic wave (SAW) is particularlyinteresting because of its ability to add a novel liquid actuation method which makes to simplify the designing oflab-on-a-chips. Up to now, we succeeded in developing (SAW) actuators for transporting continuous liquid and ahigh-efficiency liquid mixing chip using SAW actuators [1]. Meanwhile, the displacement of solid by the SAWs
had been reported [2]. If powder can be transported, we can establish a ontrolling process consisting of powder
movement, powder injection into liquid, and themselves mixing operated only by the SAWs on one-chip.
However, unlike continuously flowing liquid in a channel, spatially controlling powder transport by using theSAWs is difficult, because the powder transport direction must be aligned with an axis direction of an interdigitaltransducer (IDT) that generates the SAWs. Therefore, we changed the method for controlling the powdertransport direction by using reflected SAWs from a micro groove and succeeded in moving the powder by thereflected SAW [3]. Moreover, if the powder can be transported in not only the upstream direction but also
downstream direction of the SAWs, the flexibility of powder transportation will be enlarged in its applications.
In this paper, we propose a novel method for controlling the powder transport direction by drive frequency, anddemonstrate the validity of this method by experiments.
Figure 1(a) shows a photograph of our fabricated SAW actuator for powder transport. The SAW actuator was
fabricated by IDT (1-μm thick Al layer) patterning on a piezoelectric substrate (127.8 degree y-rotatedx-propagating LiNbO3) using photolithography. We fabricated four SAW actuators on a 4-inch wafer. Figure 1(b)shows a schematic diagram shown relationship between IDT and orientation flat of the wafer. The IDTs of the
SAW actuators were located at inclination angles θ of 0, 30, 60, and 90-deg. against perpendicular direction of
the wafer orientation flat. Here, we chose a proven IDT shape of a 200μm stripline pitch, a 5mm aperture, and 20
stripline pairs.
Experiments and Results
Figure 1(a) shows a photograph of our fabricated SAW actuator for powder transport. The SAW actuator was
fabricated by IDT (1-μm thick Al layer) patterning on a piezoelectric substrate (127.8 degree y-rotatedx-propagating LiNbO3) using photolithography. We fabricated four SAW actuators on a 4-inch wafer. Figure 1(b)shows a schematic diagram shown relationship between IDT and orientation flat of the wafer. The IDTs of the
SAW actuators were located at inclination angles θ of 0, 30, 60, and 90-deg. against perpendicular direction of
the wafer orientation flat. Here, we chose a proven IDT shape of a 200μm stripline pitch, a 5mm aperture, and 20
stripline pairs.
Figure 2 shows frequency characteristic of return loss (RL) of our fabricated SAW actuator. The RL is thelogarithmic ratio of the incident electric power PI to the reflected electric power PR and increases as the applied
power ratio to the IDT increases. At the SAW actuator with 0-deg. inclination angle, one RL peak was observed
at 19.1MHz, and then multiple peaks were observed. The 19.1MHz is the conventional drive frequency of the
SAW actuator, and corresponds approximately to the value of propagation velocity of a Rayleigh-wave(3690m/s) divided by IDT’s pitch size (200μm). On the other hand, because there existed the multiple peaks, it isconsidered that the SAW actuator had potential to generate SAWs at their peak frequencies. In the same way as
the SAW actuator with 0-deg inclination angle, there exist lots of RL peaks in the other SAW actuators with49

different inclination angles.
Next, we investigated powder transport behaviors by the SAW actuators applied at the RL peak frequencies asdrive frequencies. Figure 3 shows experimental setup for powder transport. Before starting the experiments, thepowder was uniformly spread on the wafer by a sifter. Here, for the powder we used tungstic anhydride (average
particle size of 22.3µm) in consideration of visibility and insulation. In the experiment, a function generator
created 1-kHz burst waveforms consisting of 2000 cycles of fD MHz sine waves, where, it, corresponded to theobtained RL peak frequencies. If SAWs were generated by applying the boosted voltage, the powder might betransported by the propagated SAWs. At this time, the powder transport behavior was recorded with ahigh-definition video camera.
In our experiments we could observe several powder transports by specific combinations of inclination angles
and drive frequencies. The most notable ones are that the SAW actuator with 90-deg. inclination angle could
transport the powder forward and backward with high transport efficiencies in comparison with the other SAW
actuators. The investigation powder transport characteristics with different inclination angles can be very usefulin the designomg a chip consisting of the SAW actuators for powder transport control
.
(a)
(b)

Figure 1 (a) Photograph of SAW actuator for powder transport.
(b) Location relationship between IDT and orientation flat.

Figure 2 Frequency characteristic of return loss of SAW actuator.

Figure 3 Experimental setup for observing the powder transport driven by SAW actuators.
[1] T. Saiki, K. Okada and Y. Utsumi, “High Efficiency Mixing and Pumping of Continuous Liquid Flow using Surface-Acoustic-Wave”,
13th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS2009), 58 (2009).
[2] M. Kurosawa, M. Takahashi and T. Higuchi, “Ultrasonic Linear Motor Using Surface Acoustic Waves”, IEEE Transactions on
Ultrasonics, Ferroelectronics, and Frequency Control, 43, 901 (1996).
[3] T. Saiki, H. Tomita, H. Shizuka, K. Okuda, K. Maenaka, Y. Utsumi, “Reflected Surface Acoustic Wave Actuator Using Micro Groove”,
37th International Conference on Micro and Nano Engineering (MNE2011), 490 (2011).

50

Fabrication of SERS Active Three-dimensional
Silver Nanostructure
R.Hara*,R.Takahashi*, T.Fukuoka* , A.Yamaguchi* , Y.Utsumi**Laboratory of Advanced Science and Technology for Industry, University of Hyogo
3-1-2 Koto, Kamigori, Hyogo, 678-1205 JAPANE-mail: hara099@lasti.u-hyogo.ac.jp
Phone/Fax: +81-791-58-0232
Introduction
Recently, surface enhanced Raman scattering (SERS) is attracting attention as a high sensitive analysis system.
SERS is the detection method using Raman spectroscopy and localized surface plasmon resonance (LSPR). To
enabling strong LSPR, the noble metal nanostructure like gold or silver is essential. In previous report, gold
nanoparticles were used to fabricate nanostructure. In this study, by using convective self-assembly [1] ofparticles, we developed the three-dimensional silver nanostructure (Ag3D) because low cost silver is moredesirable material for SERS active nanostructure than gold. In addition, silver is thought to be suitable for the
SERS measurement of various compounds.
Fabrication of Ag3D
We pasted silicone sheet with 6 mm throughhole on the UV-cleaned slide glass, and made a well. 5µl of themixed solution of the silver nanoparticle (AgNP) and polystyrene latex beads (PS) was dropped into the well anddried at 75 % relative humidity for about 1 day. The PS colloidal crystal was fabricated by convective
self-assembly, where AgNP were simultaneously accumulated in the gaps of the PS. The structure was soaked indichloromethane to remove PS. Thus, Ag3D was successfully obtained (Fig.1).
SERS measurements
As shown in Fig.2, unique honey-comb structure of Ag3D was fabricated at a part of the well. We
demonstrated in situ SERS measurement of 4,4’-Bipyridine (4bpy) as the Raman active molecule, using theAg3D. First, silicone sheet with 6mm throughhole was pasted to the Ag3D on the glass to make a measurement
well. Second, 35 µl of 4bpy aqueous solution was dropped into a well on the Ag3D. A cover glass was put on toprevent drying of 4bpy solution and changing of 4bpy concentration. Ag3D was set to Raman spectrometer, and
1 s irradiation of 785 nm (50 mW) laser focused on the Ag3D was started.
We observed the characteristic enhanced Raman spectrum of 4bpy (1000 cm⁻1, 1250 cm⁻1, 1580 cm-1) within 1
min after dropping 4bpy (Fig.3). SERS spectrum was only observed in the part of Ag3D, while no SERS wasobserved in the part without Ag3D. Raman spectra were enhanced about 10⁵ times, compared with the casewithout Ag3D. Although the peak of 1 nM 4bpy solution was weak, it was detectable. The case with Ag3D andthe case with Ag colloid aggregation were compared in the 4bpy peak height of 1580 cm -1 (Fig.4). SERS
measurement using Ag3D was stable even after time passed, while peak intensity drastically dropped withinminutes in the case with Ag colloid. one reason for this was that SERS active structure of Ag colloid was broken
by aggregation process over time. In addition, we succeeded in observing the chloride activation which increased
to 2-3 times in Raman intensity of 4bpy by the addition of NaCl to Ag3D (Fig.5). As a result, we have achieved
a high sensitivity SERS measurement using Ag3D. SERS activity of Ag was generally higher than Au in thecolloidal system, although obtained SERS using Ag3D [2] was still weak compared to the case using Au3D
which was consisted gold nanoparticles. There is a possibility of enabling strong SERS if Ag3D fabrication is
optimized.

.

51

PS
AgNP

Fig.1: (a) A schematic diagram of self-assembled
structure. (b) Ag3D after drying and remove PS

Fig.4: 4,4’-Bipyridine peak intensity with

Intensity

Ag3D and Ag colloid aggregation.

Fig.2: Microscopic image of three-dimensional
silver nanostructure.

8000
7000
6000
5000
4000
3000
2000
1000
0
800

blank
100uM
100uM_Cl

1200 1600 -12000
Raman Shift / cm

2400

Fig.5: Chloride activation of 4,4’-Bipyridine

3000

↓

Intensity

2500
2000
1500

100 nM
1 nM
blank

↓

1000

↓

500
0
800

1200 1600 2000 2400
-1
Raman Shift / cm

Fig.3: SERS spectra of 4,4’-Bipyridine.

References:[1] Y. Mori, N. Shinohara, and T. Fukuoka, International Workshop on Nanomechanical Cantilever
Sensors 2008, P48, 2008.
[2] T. Fukuoka, and Y, Utsumi: Rev. Laser Eng. 40 (2012) 930 [in Japanese].

52

Blood separation chip
for automated biological analysis
T.Kunisada1, H.Nose1,M.Ishizawa1, K.Kuroda1, I.Okada2 A.Yamaguchi1 and Y.Utsumi1
1

Laboratory of Advanced Science and Technology for Industry, University of Hyogo,
3-1-2 Kouto, Kamigori, Ako-gun, Hyogo 678-1205, Japan
2

Nagoya University Synchrotron Radiation Center, Japan

E-mail:takeshi@lasti.u-hyogo.ac.jp

Phone/Fax: +81-791-58-0232

Abstract
We present a chip for the blood separation using centrifugal force and capillary force. We expect that this chipcan perfome overall assay with high-efficiency and significantly shorten the analysis time by integrate our
proposed 3D lab-on-a-CD. The material of the chip which is fabricated by using X-ray lithography is SU-8 and
Si. Blood separation is done using centrifugal force by spinning the chip at a frequency of 40Hz and transport tocollection reservoir from separation reservoir using capillary force. It is necessary for capillary force to treat
surface condition. We succeed in liquid transportaion by only control spin speed.
Introduction
The lab-on-a-CD is promising for the automation of multiple microreactor systems. Recently,
high-performance immunoassay based on lab-on-a-CD has been proposed [1]. The extraction of plasma fromwhole blood is the first preparative step in many assay protocols and major importance in medical diagnosis [2].
We present a chip for the extraction of blood plasma from whole blood using centrifugal force of spin andcapillary force. We expect that this chip can be overall assay with high-efficiency and significantly shorten theanalysis time by integrate our proposed 3D lab-on-a-CD [3].
We present a chip for the blood separation using centrifugal force and capillary force. We expect that this chipcan perfome overall assay with high-efficiency and significantly shorten the analysis time by integrate our
proposed 3D lab-on-a-CD. The material of the chip which is fabricated by using X-ray lithography is SU-8 and
Si. Blood separation is done using centrifugal force by spinning the chip at a frequency of 40Hz and transport tocollection chamber from separation chamber using capillary force. It is necessary for capillary force to treat
surface condition. We succeed in liquid transportaion by only control spin speed.
Experiments and Results
We designed chip as shown in Fig.1. We formed a CHF3 plasma chemical vapor deposition (CVD) film on thecapillary valve just before the experiment. The plasma chemical vapor deposition (CVD) film with fluorine has acontact angle of over 100° [4]. By coating valve, liquid can be held until the higher rotation.
Process of blood separation is described in Fig.2. First of all, we injected whole blood into the separation
reservoir (Fig.2a). In spinning the chip blood separation was performed by centrifugal force(Fig.2b,eձ).
Rotational speed is accelerated up to frequency of 25Hz(Fig.2eղ). It was less than the burst frequency of thecapillary valve. Phase separation was caused in a centrifugal field by a difference in mass density (Fig.2c).
During blood separation, the capillary valve is used to control the flow sequence and hold liquid by surface
tension. After finishing the separation, rotating speed was accelerated above the burst frequency. Then, thecapillary valve was burst by the stronger centrifugal force (Fig.2d,eճ). Next, liquid transportation was started
and rotating speed should be decelerated to avoid disturbing rise by centrifugal force(Fig.2eմ). Liquid rose in
the capillary to the same height as the surface of liquid in the separation reservoir and reached the hydrophilic
area. As soon as liquid reached the hydrophilic area, liquid is extracted by capillary force toward the collection
reservoir. When liquid passed through the top of the capillary, rotating speed was accelerated again andextraction to the collection reservoir quickly(Fig.2eյ). Blood cells remained at the bottom of the separation
reservoir.
In this way, it is possible to control the flow sequence only controlling the rotation speed of the chip. We
expect that the proposed chip will be able to extract only plasma from whole blood automatically.

53

Capillary valve
Hydrophilic
area

30μm

Inlet

CapillaryHydrophobicareaCollection reservoir

5mm

Separation reservoir

Fig.1: Schematic of microchannel.

eFig.2: (a)-(d) Optical micrograph of each process of blood separation. (e)Protocol diagram.
References[1] S. Lai, S. Wang, J. Luo, L. J. Lee, S. T. Yang, and M. J. Madou, Analytical Chemistry, 76, 1832 ,(2004)[2] Stefan Haebelre, Thilo Brenner, Roland Zengerle, and Jens Ducree, lab chip, 6, 776-781, (2006)[3] Saki Kondo, Tsukasa Azeta, Yoshiaki kita, Yuichi Utsumi, Microsyst Technol, 16, 1577-1580, (2010)[4] M.Okada, K.Nakamatsu, Y.Kang, K.Kanda, Y,Haruyama, and S.Matsui,Applied Physics, 48, 06FH15, (2009)54

Optimization of Surface Enhanced Raman Scattering
Active Three- Dimensional Gold Nanostructure
R. Takahashi*, T. Fukuoka*, Y. Utsumi*, A. Yamaguchi**Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Koto,
Kamigori, Hyogo 678-1205, JAPANE-mail: jo-ji@lasti.u-hyogo.ac.jp, Phone/Fax: +81-791-58-0232
Abstract: Recently, Surface Enhanced Raman Scattering (SERS) attracts attention as a high sensitive
analysis system. Taking into account that one dimensional linearly connected gold nanoparticles (AuNP)[1] and two dimensional array of elongated AuNP [2] showed longitudinal localized plasmon resonanceand excellent SERS performance, three dimensional layer stacks of chain-like assembles of AuNP withnumerous particle junctions are desirable. To accomplish thick stacks, we have focused on the three
dimensional gold nanostructure (Au3D) using a casting method of convective self-assembly (CSA) of
AuNP and polystyrene latex beads (PS) [3]. In this report, Au3D with thicker stacks was developed by
optimization of AuNP and PS component in CSA and SERS measurements were demonstrated.
Fabrication of Au3D and SERS measurement: A PDMS sheet with a 6 mm through hole was attachedon the uv-cleaned slide glass, where hydrophobic PDMS wall of the 6 mm well was made acircumference of “coffee-ring” so as to pin a drop of the AuNP (8.4×1014 particles/l) and PSL (2.3×1016
particles/l) mix dispersion with various composition which were dropped into the well. Since thehydrophobic surface of PDMS also made a convex meniscus of the drop around which surface/volume
ratio was larger than other part of the drop, evaporation of water was accelerated around thecircumference. As a result, the thickly stacked self-assembles on the edge of “coffee-ring” was formed.
After soaking with dichloromethane to remove PSL, sterically-bulky Au3D with enough thickness was
obtained as shown in Fig. 1.
In situ SERS measurement was performed using Au3D and 4,4’-bipyridine (4bpy) as the Raman active
molecule. 4bpy aqueous solution (30 µl) was dropped into the measurement well, and covered with acover glass in order to prevent drying or concentration. The collection time of each SERS measurement
was 1 second (average 10 times at 0.1 second) using Raman spectrometer (RAM-100S, Lambda VisionInc., Yokohama Japan) with 785 nm laser (100 mW). As results, we succeeded in 100 nM 4bpy detection.
Optimization of Au3D: In order to obtain further SERS active structure, we performed optimization of
Au3D fabrication concerning dropping volume of mixed dispersion (3, 5, 7, 10, 15, 20 µl), the particle
number ratio (AuNP:PS = 100:1, 300:1, 1000:1, 3000:1), Au diameter (16, 22 nm) and PS diameter (100,600, 1400 nm). SERS active of the Au3D were evaluated by measuring 4bpy. As results, optimum
conditions of dropping volume, the number ratio, Au diameter and PS diameter respectively were 5 µl,
1000:1, 16 nm and 600 nm as shown in Fig. 2-4. By using Au3D of optimum conditions, we achieved
high sensitive measurement of 1 nM 4bpy as shown in Fig. 5. This enhancement reached over 107
compared with the normal Raman spectroscopy without Au3D.
In addition, we found that Au3D’s width in radial direction depended on Au particle number.. Then, thewidth of Au3D was controlled as shown in Fig. 6. By using this broad Au3D, the background from theslide glass was reduced even inexpensive Raman spectrometer without confocal system. Further highsensitive detection is expected by using broad Au3D. Furthermore, we also succeeded in the detection of
10 μM histamine and 50 μM melamine. Au3D is to be applied to the field of bioassay and food safety.

55

a

700

b

600
Intensity

500

1 μm㻌

400

100 nM
10 nM
1 nM
Blank

300
200

3 μm㻌

100
0

Fig. 1. (a) SEM image of Au3D. The diameter ofthe holes is about 600 nm. (b) Enlarged SEM
image of honeycomb network of granularassembled gold nanoparticles.

800

1000 1200 1400 1600 1800
-1
Raman Shift / cm
Fig. 5. Characteristic enhanced Raman spectraof 4bpy with different concentration (100 nM,
10 nM, 1 nM, Blank) by using optimum Au3D.

Peak Height at 1600 cm

-1

700
Blank
Au:PS=300:1
Au:PS=1000:1
Au:PS=3000:1
Au:PS=5000:1

600
500
400

a

300

b

200
100
0

1nM

10nM

50nM

4,4'-Bipyridine concentration

Fig. 2. Optimization of Au3D for SERS activity.
Effect of particle number ratio (AuNP:PS).

c

Peak Height at 1600 cm

-1

700

d

Blank
16 nm
22nm

600
500
400
300

10 µm

10 µm

200

Fig. 6. Changes in Au3D width in radial
direction depending on the particle number. (a)14
0.5×8.4×10
particles/l 14 (b) 8.4×1014

100
0

1nM

10nM

50nM

particles/l14(c) 2.5×8.4×10
5×8.4×10 particles/l.

4,4'-Bipyridinepy
concentration

Fig. 3. Optimization of Au3D for SERS activity.
Effect of Au diameter.

-1

Blank
600 nm
1400 nm

400
300
200
100
0

1nM

particles/l (d)References:[1] T. Fukuoka, J. Jpn. Inst. Electron.
Packaging (Electronics Jisso Gakkai Shi),
13(3), 168-176(2010) (in Japanese).
[2] M. Suzuki, K. Nakajima, K. Kimura, T.
Fukuoka, and Y. Mori, Anal. Sci., 23(7),829-833(2007).
[3] Y. Mori, N. Shinohara, and T. Fukuoka,
International Workshop on Nanomechanical
Cantilever Sensors 2008, P48, 2008.

500

Peak Height at 1600 cm

10 µm

10 µm

10nM

50nM

4,4'-Bipyridine,py
concentration

Fig. 4. Optimization of Au3D for SERS activity.
Effect of PS diameter.

56

Fabrication and characterization of three-dimensional
type micro magneto-impedance sensor
1

T. Yamamoto1, Y. Yoritama1, T. Uchiyama2, Y. Utsumi1 and A. Yamaguchi1
Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Koto, Kamigori-gun, 6781205, Japan.
2
Graduate School of Engineering, Nagoya University, Chikusa, Nagoya, 464-8603, Japan.
Abstract
Fabrication and evaluation of a three-dimensional micro-scale magneto-impedance (MI) sensor
have been carried out. We present the detail of the fabrication process of the device and themeasurement result of the impedance of the sensor head. The measured characteristics indicatethat we succeeded the fabrication of the three-dimensional micro-scale MI sensor.

Introduction
In recent years, the people's concern about their health is increasing under the influence of aging society inadvanced nations. Physical changes caused by external factor will be offset by the action of the autonomic nerve
system. This indicates that the human health state depends on the autonomic nervous system. An un-invasive
healthy monitoring system is required for the estimation and control of each of health status. The system consistsof near-infrared spectroscopic devices for detecting the amount of substance inside blood and integrated
magnetometric sensors to measure the dynamic characteristics of human’s circulatory organ system as one of thefunction of the autonomic nervous system at the same time.The circulatory system response from themeasurement results enable us to create the mathematical model which relates the response with exogenous
stimulus. Therefore, health-maintenance medicine will be achieved by this model applied to the signal obtained
from the sensor.
We need the high sensitive sensor in order to achieve the model. The change in the high frequency
impedance of very soft ferromagnetic materials upon the action of external static fields, known as magnetoimpedance (MI) effect, has been intensively studied for magnetic sensor applications.[1, 2] The high sensitive
MI effect occurs when high frequency current is applied to the amorphous metal in which spin is arranged
circumferentially. The MI sensors using MI effect has been recently attracting attention for improved theresolution of up to 10-12 T [1], which can measure bio-magnetic field in range from 10-10 to 10-15 T. The
significant change in impedance is basically derived from the skin effect. The estimation of the high sensitivityof magnetic field is of great importance for the sensor application. The development of the general estimation
method for the only inductance component of impedance also provides an insight to understanding the physicalmechanism with respect to the relationship between the skin effect and micro- or nano-scale magnetization
structure.
Experiments and Results
In this study, integrated coil, made of gold Au, is fabricated using UV lithography and succeeding packaging
method to improve productivity. The Fe21.5Ni78.5 (Permalloy: Py) wire with thickness of 60 nm is prepared in thecoil. The devices were fabricated by building up SU-8 layers as shown in Fig. 1. The fabrication process is also
schematically illustrated in Fig. 1. Finally, one side of the device is covered with Kapton film for electricalinsulation. Its size is 1.5 mm in length, 1 mm in width, and the thickness is 35 m. The optical image of thedevice is shown in Fig. 2. In our device, the inductance component of impedance can be detected by not only thePy wire itself but also a pickup coil formed around the Py wire.
To evaluate the impedance of the device, we measured the impedance of the device as a function of thefrequency (from 100 Hz to 100 MHz) by using a MI sensor electrical circuit device. As shown in Fig. 3, theimpedance was rapidly increased with a frequency up to a 10 % when the frequency exceeded at about 20 MHz.
The change in the impedance is attributable to not the ferromagnetic resonance but the normal skin effectbecause the ferromagnetic resonance frequency is far higher than the measured frequency region.
Although further systematic investigation is necessary in order to perfectly understand the physicalmechanism and evaluate the MI effect, we have succeeded in fabricating a novel integrated MI sensor by means
of UV lithography fabrication technique. The implementation of high sensitive MI sensors can provide
biomedical monitoring system, car sensors and so on.

57

Fe-Ni Sensor headFig. 1 Schematic of fabrication process and device.

(a)

(b)

Fig. 2 Optical images of (a) the fabricated MI Sensor and (b) magnified coil region.

Fig. 3 The frequency dependence of the impedance of the fabricated MI sensor.
References[1] T. Uchiyama, A. Yamaguchi, Y. Utsumi., J. Magn. Soc. Jpn., 34(Japan, 2010).
[2] K. Mori., Magnetic Sensors (Tokyo, Japan, 1998).

58

Micro-Mirror Array Device for floating image
manufactured by Synchrotron radiation
T.Yamanea, S.Maekawab, I.Okadaa,c ,Y.Utsumia and A.Yamaguchia
Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori,
Hyogo 678-1205, Japanb
National Institute of Information and Communications Technology,3-5 Hikaridai, Seika, Soraku, Kyoto, Japanc
Nagoya University Synchrotron radiation Research center, Furocho ,Nagoya Chikusa-ku, Aichi 464-8603, Japana

Abstract
We propose a new imaging optics called the Dihedral Corner Reflector Array (DCRA) which is designed tomake the floating image. DCRA consists of numerous micro-mirrors placed perpendicular to the surface of
substrate. The micro-mirror array is implemented by the inner walls of minute square holes or the side ofminute square pillar. We can choose two types of the structure. The primordial is based on two reflections
by a pair of adjacent mutually perpendicular mirrors, i.e., a dihedral corner reflector. (S.Maekawa 2006.)
Although the principal of operation is based on reflection by mirrors, the device is also transmissive anddeflects light. Primordial of DCRA is not so complicated. However, it is too difficult to fabricate the DCRA
by usual machining because of high aspect ratio micromachining. Therefore, in this manuscript, wefabricated the device by deep X-ray lithography due to synchrotron radiation. The characteristics of thefabricated DCRA are evaluated by the optical transmission and reflection measurements.
because incident light is reflected twice when passing
through a dihedral corner reflector. In the case of
two-dimension structure, an incident light from a lightsource “A” is reflected in the direction “B” parallel to thelight source “A” as shown in Fig. 1(a). Next, let us
consider that the incident light from “A” into a dihedral
corner reflector reflects two times at the mirrors anddeflects toward the point “B” in 3D structure as shown in
Fig. 1(b). Then, if the micro-mirrors are extremely small,the incident light passes through the substrate plane
toward the symmetric point for the light source. When we
prepare many dihedral corner reflectors on the substrate,
all the light from a light source is converged onto thereflection-symmetric point of the source. As a result, thearray of numerous dihedral corner reflectors, namely
DCRA, can realize the floating image. (S.Maekawa 2006)

Introduction
There are some basic imaging optics which can form areal image, such as convex lens, a concave mirror, anddiffraction optics (a Fresnel lens). For example, there aresystems which are based on the lens array of the GradedIndex Lens (GRIN) (H.Kita et al 1971), Roof Mirror Lens
Array (RMLA) (M.Kawazu et al 1985), and the stackingof various micro-lens arrays (R.Volkel et al 1996). These
have an optical axis and a specific focal length. Moving
an object closer to the optics, the real image forms farther
from it and is magnified. In contrast, imaging optics canform three-dimensional (3D) images without distortion.
An example of this is a plane mirror. However, as a plane
mirror can only form virtual images, the world in the
mirror is treated as fantasy.
The authors of this paper propose a new imaging optics
forming a real mirror image with the use of micro-mirrors.
We called this imaging optics as the Dihedral Corner
Reflector Array (DCRA).

Image-formation and precision of DCRA
Here, we postulate that the transmittance of DCRA is thepercentageofincident
light
throughthereflection-symmetric point. The transmittance is given by
where I is the ideal transmittance, R is reflectance of
micro-mirror, and T is the losses, which is defined as theattenuation of intensity of the incident light after passing
through the DCRA.
Reflectance of micro-mirrors is the most importantfactor in imaging by DCRA. In this study, we expect that
it is as close as possible to 100%. However, in the device,
the micro-mirrors placed perpendicular to the surface of
substrate. Therefore, no one can be polished after
manufactured.
Accordingly,
reflectanceofmicro-mirrors is determined during the creation of the
DCRA.
The perpendicularity of dihedral corner reflector plays
an important role on the resolution of the imaging, and it(a)(b)
Figure 1 Operation mode of (a) two-dimensional- and (b)three-dimensional-dihedral corner reflectors.
The primordial of DCRA
The primordial of DCRA is based on mirror reflection.
Figure 1 describes the operation of dihedral cornerreflector. The reflection mode of DCRA is limited,59

radiation (SR). The fabrication process using the SR
enables us to fabricate the DCRA structure within thelimit of accuracy of about 1 nm. Figure 2 shows
schematic of dimensions of our DCRA device. As shownin Fig. 2, a dihedral corner reflector is made by a pillar
with square section.
The incident light through inside of pillars made ofPMMA in pillar patterned DCRA. Considering thePMMA refractive index, we design the aspect ratio(height/width) of our device is two in order to achievethat the theoretical value of light transmittance of ourdevice is expected to be 100%. The aperture ratio, namely
the portion of the opening, is determined by the pitch
between the reflectors. We estimate the effective fraction
transmitted of our device is 64.9% considering thecontribution of the aperture ratio. Expressed in anotherway, the brightness of the floating image is expected to be
64.9% with the respect to that of an object. The
dimension and desired values of DCRA are summarizedin Table.1.

causes the distortion of the image. The dependence of theperpendicularity of the wall of DCRA can be estimatedby using the simulation. This simulation enables us tocalculate that the ray trace through position of lightreflected by a line of plane mirrors from point light. Then,
we can choose the value of the number of the plane
mirrors, the distance of point light to the head mirror andthe taper of mirrors. If the planes of mirrors in the DCRA
are exactly perpendicular, all the reflected light by eachmirrors pass through the same position of the head mirror.
The floating image produced by the DCRA can be
estimated to be distorted up to 10 µm when the plane
mirrors have 1 minute taper.
Image resolution is determined by the dimension of thedihedral corner reflector. The higher resolution image canbe obtained, the smaller dihedral corner reflectors in the
DCRA are fabricated. However, the image produced by
the smaller DCRA will darken because the diffractive
component of the light increases.

Figure 3 Schematic of transmission-reflection ratio
measurement system.
is an angle between theperpendicular direction of the incident light axis andsample horizontal plane.
is an angle between theperpendicular direction of the light axis and detector.

Figure 2 Schematic of the DCRA device designed inthis study.
Table 1 Dimension of DCRA
Length of square side [µm]150
Pillar height [µm]300
Pitch [µm]25
Ideal transmittance [%]100
Aperture ratio [%]64.9
Perpendicularity [deg]90
Roughness [nm]
10

(a)

(b)

Fabrication of DCRA
Polishing the micro-mirrors is easy if they are parallel tothe device surface. However, because micro-mirrors areperpendicular to the device surface in the DCRA, it is
impossible to polish them in pre- or post- processes.
Therefore, the micro-fabrication of high precision isrequired for the fabrication of DCRA. In this manuscript,
we fabricated the pillar patterned DCRA made of
Poly-methyl methacrylate (PMMA) by using synchrotron

Figure 4

Optical microscope image of (a) top view and(b) cross section of the pillars in our DCRA.

60

Table 2

found the single reflection was extended in therange
betweenandbecause the reflected light was
spread by the distortion due to the taper. The actual
fraction transmitted is estimated to be 5.4% by
substituting the measured value into Equation (1). This
indicates that a dark floating image is formed by the
fabricated DCRA. However, we succeeded in forming thefloating image by the fabricated DCRA as shown in Fig.
7.
The improvement of fabrication process and evaluationof the DCRA will open the door to the novel imaging
devices.

Dimension of the fabricated DCRA(x) 150.92

Length of square side [μm](y) 151.42
Pitch [μm]25.87

Pillar height [μm]326.78Perpendicularity[minute]

5.8

Results and discussion
Up to now, the criteria and evaluation method for theproperties such as the resolution and brightness of theimage produced by the DCRA have not yet been
established. In this study, we evaluate the characteristicsof the fabricated DCRA by measuring the dimension,
perpendicularity of the reflector, fractional transmitted
and reflection. The attenuation of brightness andreflection ratio are measured by transmission-reflection
ratio measurement system as shown in Fig.3.
Figures 4(a) and 4(b) show a typical optical
microscope image of top view and cross section of the
micro-pillars in the fabricated DCRA, respectively. The
measured average dimensions of the DCRA aresummarized in Table 2. The measured dimensions except
the perpendicularity are almost in good agreement withthe design dimensions. The perpendicularity of thefabricated pillars have about 6 minute taper. The
evaluation using the simulation indicates the taper
structure causes the distortion of 65 μm with respect tothe distance of light source. This distortion is serious forthe observation of a floating image formed by DCRA.
Next, the attenuation of brightness is evaluated by thetransmission-reflection ratio measurement system shownin Fig. 5. The measured fraction transmitted was about
40%, being in acceptable range of the design. As shownin Fig. 5, we can see a broad change from 400 nm to 600
nm in wavelength. The change corresponds to theabsorption derived from the discoloration of PMMA bySR.
Finally, the reflection ratio was evaluated by using thesame measurement system. Here, the coordinate system isdefined as shown in Fig. 3. In order to evaluate theangle dependence of the single reflection of the DCRA
at 700 nm in wavelength, we fixed the DCRA at theangle. The measured angle
dependence ofthe reflection is shown in Fig. 6. As shown in Fig. 6, tworeflection peaks are observed. The peak with the larger
amplitude (at about) corresponds to therefractive incident light. The other is the single reflectionof the light by the DCRA. If the ideal DCRA was
fabricated, we would obtain the single reflection peakatin this experimental setup. However, we100

absorption[%]

80
60
40
20
0
400 500 600 700 800 900 1000

wavelength[nm]Figure 5

Absorption as a function of wavelength.

70
60

reflection[%]

50
40
30
20
10
0

0

18

36

54

72

angle[deg]Figure 6
DCRA.

61

The angle

dependence of the fabricated90Figure 7 A typical floating image is imaged by the
fabricated DCRA.
Conclusion
We proposed novel imaging optics with micro-dihedral
corner reflector arrays (DCRA) which can form areflection-symmetric image as a real image in the air. It
was fabricated by synchrotron radiation. We evaluatedthe fraction transmitted and single reflection of thefabricated DCRA by the optical measurement system.
Although the performance of the DCRA was not good,
the fabricated DCRA enables us to observe a floating
image. By comparing the simulation result with theexperimental evaluation, we can understand what worsen
the performance of the DCRA.
Our main work to improve imaging in the future is toincrease transmittance and establish the quantitative
measurement method of resolution and reflection ratio.
Reference[1] S.Maekawa. “Transmissive Optical Imagin Device
with micromirror Array” The international society for
Optical Engineering, Vol. 6392, 63920E-1, 2006.
[2]
H.Kita, I.Kitano, T.Uchida, and M.Furukawa,“Light-focusing glass fibers and rods,” Journal of theAmerican Ceramic Society 54, pp. 321-326, 1971.
[3] M.Kawazu and T.Inokuchi, “Imaging Device using
a roof micro lens array,” Applied Optics 24(24),pp.4300-4306, 1985.
[4] R.Volkel, H.Herzig, P.Nussbaum, and R.Dandliker,“Microlens array imaging system for photolithography,”
Optical Engineering 35(11), pp.3323-3330,1996.
[5] M.Ishikawa, “A proposal to create the impression ofa miniature garden, and the development of a glasses-freesmall 3d display”, Pioneer R&D 12(3), pp.47-58, 2003.
In Japanese.

62

Broadband noise spectroscopy of a magnetic wire
A. Yamaguchi1, K. Motoi2, H. Miyajima2 and Y. Utsumi1
1

Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Koto, Kamigori, Ako,

Hyogo 678-1205, JAPAN
2

Department of Physics, Keio University, Hiyoshi, Yokohama, Kanagawa 223-8522, JAPANE-mail: yamaguti@lasti.u-hyogo.ac.jp
Tel: +81-791-0041

Abstract
We measured broadband magnetic noise spectrum induced in a single layered Ni 81 Fe 19 nano-scale
wire biased with a dc-current in a frequency range from 500 MHz to 8 GHz. The magnetic noise
spectra are recorded as a function of external magnetic field and dc-current. Experimental
measurement results and analytical calculations reveal that the noise generation is caused by thethermal magnetization fluctuation due to ambient temperature and Joule heating.

Introduction
The spin dynamics in a nano-scale magnet with a confined structure has gained increasing attention
over the last decades due to the scientific and technological interest. [1] To understand the mechanismof the spin dynamics from a microscopic perspective, the special instrumentality and measurement
system, such as magneto-optic Kerr effect, Brillouin light scattering and ferromagnetic resonance, arerequired until now. [1] Several electrical measurements that are suitable for investigating the spin
dynamics in nano-scale magnets and are extremely sensitive have been proposed recently. One of themis the homodyne detection of the resistance change induced by the spin-transfer torque and magnetic
fields. The magnetic noise measurement of a nano-scale magnet, in particular for giant
magnetoresistive (GMR) devices and tunneling magnetoresistive (TMR) devices, can be used as othertools. [2, 3] The GMR or TMR noise tests are nondestructive and can be applied to the read heads forthe magnetic hard disk drive. For diagnostic testing, we interested in the noise induced by the
spin-transfer torque, magnetic fields and thermal excitation. [2-4]This paper reports our investigation of broadband noise spectroscopy in a single layered Ni 81 Fe 19(Permmalloy: Py) wire.

Experiments and Results
The soft-ferromagnetic Py nano-scale wire is fabricated onto a polished MgO (100) substrate bymeans of high-resolution electron beam lithography with a standard lift-off technique. The thickness,
width and length of the prepared Py wire are 20 nm, 2.2 µm and 100 µm, respectively. The wire isplaced between the center strip-line of the coplanar waveguide (CPW) comprising Au conductive strip
with thickness of 100 nm. The optical micrograph image and schematic circuit diagram for broadband
noise measurement are shown in Fig. 1.
Figure 2 shows the homodyne detection spectrum (black solid line) [5] and the lock-in detection
noise spectrum (red solid line). It should be noted that the resonance frequency around 3.8 GHz of themagnetization fluctuation signal almost matches that of the homodyne detection spectrum, indicatingthat the origin of the noise signal induced by dc-current is the same as that of the homodyne detection
signal. We also measured the magnetic field dependence of the broadband noise spectra. As a result,
the resonance frequency correlates well with the ferromagnetic resonance frequency, and theamplitude of the noise signal at the resonance frequency decreases with increasing the static field.
These experimental results suggested that the measured noise signal is derived from themagnetization precession induced by the thermal fluctuation. The present experimental results are ingood agreement with the analytical solutions. [2-4] We believe this study provides not only theimportant physics on the fundamental limitation in the possibility of the scale-down size but also theimprovement in the read heads and in the radio-frequency devices.

63

Fig.1 Optical micrograph image of the Py wire and schematic diagram of the broadband noise measurement
circuit.

Fig. 2 Homodyne signal spectrum and broadband noise spectrum in magnetic field of 100 G at θ = 45°.

References[1] B. Hillebrands and K. E. Ounadjela, Spin Dynamics in Confined Magnetic Structures (Springer, Berlin,2003), Vols. 1 - 3.
[2] N. Smith and P. Arnett, Appl. Phys. Lett. 78, 1448 (2001).
[3] K. B. Klaassen, J. C. L. van Peppen and X. Xing, IEEE Trans. Magn. 93, 8573 (2003).
[4] V. Safonov and N. Bertram, Phys. Rev. B 65, 172417 (2002).
[5] A. Yamaguchi, K. Motoi, A. Hirohata, H. Miyajima, Y. Miyashita, and Y. Sanada, Phys. Rev. B 78,
104401 (2008).

64Defect Characterization of an EUV Mask using a Coherent
EUV Scatterometry Microscope
Tetsuo Harada1,2, Masato Nakasuji1,2, Akifumi Tokimasa1,2, Yutaka Nagata2,3, Takeo Watanabe1,2, and Hiroo
Kinoshita1,2
1 Center for EUV Lithography, Laboratory of Advanced Science and Technology for Industry, University of
Hyogo, Kamigori, Hyogo 678-1205, Japan
2 Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi,
Saitama 332-0012, Japan
3 Laser Technology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
Abstract
On extreme-ultraviolet (EUV) masks, phase structures such as bumps or pits on the substrate orparticles buried in the multilayers can form printable defects at EUV exposure tool. Property ofthese defects is required for mask repair by defect hiding and compensation methods using theabsorber pattern. We have developed a coherent EUV scatterometry microscope (CSM) to observe
EUV masks, which uses a simple lensless system to record a diffraction image from mask patterns.
We introduce preliminary observation results for programmed phase defects. We evaluated thedefect width and height from the diffraction images, and the detection limit of the CSM systemreached a width of 220 nm. To characterize small defects, we proposed a micro-CSM system that
focused to the illumination onto the defect with a 100 nm diameter. The diffraction image recordedby the micro-CSM system provides raw defect data, which is essential for defect compensation.
absorber pattern to compensate the aerial image.
Detailed defect information, such as defectposition on the mask, defect size, and phase
distribution, is necessary for the compensation
process. However, the ABI tool is specificallyintended for defect detection, for which themagnification requirement is not high. The spatial
resolution is determined by the CCD pixel size,
where one pixel integrates the scattering signal
from a 500×500 nm2 region on the mask. It is thus
difficult to use the ABI tool to characterize thephase defect information. In this study, weobserved the phase defects using a coherent EUV
scatterometry microscope (CSM), which is alensless type of microscope.15-19) The CSM records
the diffraction from the mask directly using a CCD
camera. We discuss the requirements for a defectcharacterization tool based on the preliminary
observation results for programmed defects. We
also propose a micro-CSM system for defectcharacterization, which focuses the illumination
onto the defect with a 100 nm diameter.

Introduction
In extreme-ultraviolet (EUV) lithography,
defect-free mask production is one of the criticalissues for high-volume manufacturing. A mask is amaster pattern for a semiconductor device, andthere must be no defects on this mask. In EUV
lithography, the EUV mask is a reflective typemask, unlike the transparent-type mask used forconventional 193 nm lithography. The EUV mask
is coated with a Mo/Si multilayer, and an absorberlayer, in which patterns are printed to form adevice pattern. However, phase structures such as
bumps or pits on the substrate or particles in themultilayers can form printable defects. For
example, a shallow structure of 1 nm on thesurface of a mask substrate causes a large
reflection phase shift of 53° at EUV wavelength.
As a result, this buried defect is printable.1-6)
Buried defects can be detected efficiently at themask blank stage of manufacture, which is justbefore the deposition of the absorber layer. The
Selete and EIDEC groups have developed an
actinic blank inspection (ABI) tool to detect phase
defects.7-10) The ABI tool is a dark-field EUV
microscope
composedofadischarge-produced-plasma
sourceand
Schwarzschild optics, which collects scattered
EUV light from buried defects to form a dark-field
image on a charge-coupled-device (CCD) camera.
Because the defect signal is integrated in a
dark-field, the ABI tool has a good signal-to-noise(S/N) ratio for the detection of defects.
Current EUV masks do not satisfy defectdensity requirements.11,12) As a result, defect hiding
and defect compensation methods have also been
proposed,13,14) which work by modifying theExperiment
We observed the phase defects using the CSM
system shown in Figs. 1 and 2. The CSM system
was installed at the BL-3 beamline of the
NewSUBARU synchrotron radiation facility,20)
which uses a bending magnet as a light source.
Two toroidal mirrors collimate the white light into
the CSM system. Figures 1 and 2 show aphotograph and a schematic view of the CSM
system, respectively. A pinhole with a 5 µm
diameter is exposed with the collimated EUV
beam and the beam diameter is then reduced to
improve the spatial coherence. A concave spherical65

mirror and a plane turning mirror are then used toreflect the beam onto the EUV mask, and thus thepinhole image is relayed to the mask. The radius ofcurvature of the concave mirror is 200 mm, andthe distance from the pinhole to the concave mirror
is 200 mm, which is the same as the distance fromthe concave mirror to the mask. The mirrors arecoated with 40 pairs of Mo/Si multilayers.
Diffraction from the mask is recorded using a
back-illuminated CCD camera. The CCD surface
is placed parallel to the mask surface. The imaging
area is 27.6×27.6 mm2, and contains 2048×2048
arrays of imaging pixels with an area of 13.5×13.5µm2. The angle of incidence from normal is 6° on
the EUV mask, which matches the angle used incurrent EUV lithography scanners. The distancefrom the mask to the CCD camera isapproximately 100 mm, which is equivalent to anumerical aperture (NA) of 0.14. The estimatedspatial resolution is 59 nm.
A phase defect scatters EUV light illumination,
where the signal depends on the phase distribution.
When using conventional imaging optics, thisphase distribution is recorded as a small dark spot
on the detector caused by destructive interference.
High magnification is required to characterize thedefect. In contrast, the CSM can record thescattering signal directly, including the complex
amplitude information of the defect. We havesuccessfully reconstructed edge structure ofline-and-space pattern from these scattering signals
using a coherent diffraction imaging method.21-27)
We have also succeeded in reconstructing both anintensity image and a phase image.19)
The sample mask was a blank EUV mask,
which contained programmed bump structures ona glass substrate. The bumps were located with a
10 µm pitch. The bump height was 7 nm, and thebump width was varied, ranging from 70 to 420
nm, with a square shape.

Fig. 2 Schematic view of the CSM system.
Results
Figure 3 shows a diffraction image with aphase defect recorded using the CSM. The
exposure time was 1,000 s. The intensity is shownin log scale. The defect was 420 nm wide and 7 nm
high, as measured by atomic force microscopy(AFM). This defect had a truncated-pyramid shapewith slope width of about 70 nm. The strong
diffraction signal around the defect center wasfrom the illumination. The Fraunhofer diffraction
from the 5-µm-diameter entrance pinhole wasrecorded at the center position, as shown in Fig. 3.
The illumination profile was asymmetric, because
the small turning mirror limited the illumination
pupil size. The center illumination signal was
saturated because of the long exposure time, andthe intensity was estimated to be 8.8×105 counts
from other data with shorter exposure times.
Because the cross-shaped diffraction signal aroundthe illumination came from the defect, the defectshape was determined to be a square. The
diffraction signal intensity was about 30 counts,
which was 10-4 times weaker than the intensity at
the illumination center. The defect width wasestimated to be about 430 nm from the diffraction
width of the crossed line, which corresponded wellwith the AFM value. The defect height wasestimated to be 6.5 or 7.0 nm from the diffraction
intensity ratio of the center to the crossed parts.
The reflection phase change of the height was
equal to 13.0 or 14.0 nm, which was a differenceof 0.5 nm (0.23 rad) from the 13.5 nm EUV
wavelength. Thus, the estimated height also
corresponded well with the AFM value. We
therefore successfully evaluated the defect widthand height precisely using the CSM system.
Figure 4 shows diffraction images of defects
with widths of (a) 420, (b) 220, and (c) 130 nm,
and image (d) without a defect. The intensity was
shown on a linear scale. All the defect heights
were about 7 nm. The defect of 220 nm width also
had a truncated-pyramid shape. Thus, the slope
widths of (a) and (b) were about 70 nm at bothsides, which was measured by AFM. That of the
130 nm-wide defect had a Gaussian shape. At thedefect width of 420 nm shown in Fig. 4(a), thediffraction shape was easily recognized as a cross.
However, because the diffraction spread to all

Fig. 1 Photograph of the CSM system. The arrows
show the light path of the synchrotron radiation.
The CCD camera records diffraction from the
EUV mask pattern.

66areas of the image of the 220 nm defect shown in
Fig. 4(b), the defect shape could not be recognizedwith certainty. For the 130 nm defect, thediffraction intensity was almost the same as that of
the sample without the defect. This signal was
found to be speckle diffraction from the substrateroughness, which overlapped and hid the defectsignal in the background. Figure 5 shows thediffraction signal profile of the indicated area
shown in Fig. 4(a) as a white square. The centersignal of the diffraction profile included the
speckle noise signal of the fringed shape. The
outside impulse signals were caused by the CCD
camera noise. The profile of the 130 nm defect(dark-gray solid line) was similar to that of theimage with no defect (dotted line), because thesignal from such a small defect was hidden by the
speckle noise.
The speckle noise was observed in the blankarea with this mask. However, speckle noise was
not observed in the other mask shown in Fig. 6.
The exposed region was also a blank region
without defects, where no speckle noise wasrecorded. The speckle signal was thus strongly
dependent on the surface roughness, and would
therefore degrade the detection limit size andprecision of the defect characterization of the CSM
system. George et al. reported that this speckle
noise affects the line edge roughness.28) As a result,the surface should be smooth not only for
multilayer reflectivity, but also for the aerial image
quality. From the point of view of roughness
evaluation, the CSM system was able to evaluate
the actinic surface roughness of mask blanks
precisely because it recorded the substrate speckle
clearly. In comparison with another method using aphotodiode detector29,30), the CSM can record thetwo-dimensional speckle profile with a better S/Nratio, and evaluate the effect of speckle on theaerial image.

Fig. 4. Diffraction images of programmed phase
defects of (a) 420, (b) 220, and (c) 130 nm width, and(d) an image without a defect. The intensity is shown
on a linear scale.

35
Defect Width
420 nm
220 nm
130 nmNo Defect

Signal (counts)

30
25
20
15
10
5
0
0

200

400
600
Position (pixel)

800

1000

Fig. 5. Intensity profile of the diffraction signals forthe defects. The horizontal axis indicates the image
position shown in Fig. 4(a).

Fig. 3. Diffraction image with a programmed phase
defect with 420 nm width and 7 nm height. The
intensity is shown in log scale.

Fig. 6. Diffraction image of a mask blank without
defects. There is no speckle noise signal.
Discussion
4.1 Concept of micro-CSM system
The CSM system can evaluate defect properties

67

diameters of (a) 1 µm and (b) 100 nm. The
intensity is shown in log scale. The maximum NA
position of the image was 0.5. The strong signal at
the center originated from the illumination. The
weak signal of the outside ring was a diffraction
signal that came from the defect. For the
1-µm-diameter case, the speckle noise overlaps thedefect signal. For the 100 nm case, there was nospeckle noise, and the defect signal was recorded
clearly. The intensity profiles of these images areshown in Fig. 9. The horizontal axis indicates the
NA position at the detector, and the vertical axis
indicates the signal intensity. The NA position
corresponds to the diffraction angle. The intensitiesof the 1-µm- and 100-nm-diameter cases werenormalized for the same illumination intensity. In
the 1 µm case, the illumination peak signal was
two orders stronger than that in the 100 nm case,while the defect signal was two orders weaker. The
signal range spanned seven orders of magnitude,from 10-5 to 102. Because a typical CCD camera
has a dynamic range of 4 orders of magnitude, it isdifficult to record the defect signal using a CCD
camera. Also, the speckle signal overlapped thedefect signal, which was the same as that shown in
Fig. 5. In the 100-nm-diameter case, theillumination and diffraction signal were recordable
within three orders of magnitude, and no speckle
signal was recorded. We thus chose theillumination size of 100 nm for the micro-CSM
system, allowing the characterization of the defectusing the CCD image.
We also simulated the diffraction signal profile
from various sizes of defects with the
100-nm-diameter illumination. Figure 10(a) shows
the diffraction signals from a defect with various
heights ranging from 0 to 3 nm, while the width
was fixed at a diameter of 50 nm. Figure 10(b)shows the diffraction for various diameters,
ranging from 0 to 60 nm, while the height was
fixed at 1 nm. The horizontal axis indicates NA
positions at the detector same as Fig. 9. The
illumination was assumed to have a top-hat
intensity distribution for simplicity. Because theillumination size and the defect size werecomparable for these conditions, the center signal
decreases over 10% by destructive interferencewith the shallow 1-nm-height defect. Under these
conditions, the defect position was detectable fromthe intensity change of the illumination signal.
This was very useful for location of the defectposition. Because the ABI tool has a low spatial
resolution of 500 nm, scanning of the illumination
using the micro-CSM system is necessary tocharacterize defects that are detected by the ABI
tool. The diffraction profile for a tiny defect with awidth of 20 nm was clearly different to the
no-defect case. Thus, the detection limit of a defectsignal using the micro-CSM is better than a defectwith 20 nm width and 1 nm height, if the mask has

without any influence from the imaging optics.
The CSM measured the defect width and heightfrom the diffraction signals. However, small defectsignals were hidden by the speckle noise because
the defect signal was weak relative to the strong
speckle noise from the surface roughness. Also, theillumination signal was 104 times stronger than thedefect signal, making bright-field observationdifficult. To minimize the noise and maximize thedefect signal intensity, the illumination size should
be as small as the defect size, which improves thedefect-to-illumination size ratio. Thus, we propose
the micro-CSM system shown in Fig. 7. The
micro-CSM system has almost the same optics as
the CSM system. The specific additional
component in the micro-CSM is a Fresnel zone
plate (FZP) that focuses the illumination onto asmall phase defect. The FZP has an off-axis zone
aperture, as shown in Fig. 7. Also, the diffraction
from the defect transmits a rectangular aperture to
the FZP membrane, which is recorded with a CCD
camera directly. The target defect size of the
micro-CSM system is 20 nm in width and 1 nm inheight.

Fig. 7. Schematic view of micro-CSM system.
Monochromatized EUV light is focused onto a defectby an off-axis Fresnel zone plate.
4.2 Simulation of diffraction intensity profile
We simulated the diffraction signal from thedefect with various illumination sizes to optimize
the micro-CSM system. This simulation was basedon scalar diffraction theory. The simulation
conditions are as follows. The working wavelength
was 13.5 nm. The illumination was focused using
optics with an NA of 0.17. The angle of incidence
was normal. The reflection from the multilayers on
the substrate was assumed to be a reflection from asingle layer for simplicity. The phase defect had asymmetrical circular shape, and a top-hat phase
distribution. For speckle noise calculations, thereflection layer had a surface roughness of 0.15 nm(rms).
Figure 8 shows diffraction images from a phase
defect with a diameter of 50 nm and a height of 1
nm. The illumination sizes were varied, with68

a low surface roughness of 0.15 nm (rms) and thesensor noise is negligible. Because the diffraction
signals are very sensitive to the defect height andwidth, the micro-CSM can characterize the defectproperties precisely.

Fig. 10. Diffraction intensity profile with defects withvarious (a) widths and (b) heights.

Fig. 8. Calculated diffraction images with illumination
diameters of (a) 1 µm and (b) 100 nm. The defect has
50 nm diameter and 1 nm height. The substrate has
0.14 nm (rms) surface roughness.

Conclusions
Programmed phase defects on EUV mask
blanks were observed using the CSM system. The
CSM successfully detected phase defects down toa width of 220 nm, and we evaluated the defectwidth and height precisely for the 420 nm defect.
This defect property information is important for
repair using defect hiding and compensation
methods with absorber pattern modulation.
However, because the illumination diameter was aslarge as 5 µm, the defect signal was too weak. Also,
the speckle noise signals from the substrates hid
the defect signals for defect sizes smaller than 200
nm. We therefore proposed the micro-CSM system,
which focuses the illumination onto the defect witha 100 nm diameter. Simulation results show thatthe micro-CSM system can record the diffraction
signal clearly from a defect with a diameter of 20
nm and a height of 1 nm. As a result, themicro-CSM can characterize the defect properties.
In a future work, we will construct the micro-CSM,
and collect diffraction images from various
programmed defects and actinic defects. The
database relations between the ABI signals and themicro-CSM signals will help to enhance the ABI
performance. The diffraction images recorded
using the micro-CSM provides raw defect data,
which is essential for defect compensation.

103

Intensity (arb. unit)

102
101
100

Focus size
φ100 nm
φ1 µm

10-1
10-2
10-3
10-4
10-5
10-6
-0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5
Numerical Aperture

Fig. 9. Intensity profiles of the calculated diffraction
images shown in Fig. 8.

Acknowledgements
This work is a part of re-contracted researchfrom the EUVL Infrastructure Development Center(EIDEC). EIDEC programs are supported by the
New Energy and Industrial Technology
Development Organization (NEDO).

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70

Chemical Reaction Analysis of EUV CA Resist using SR
Absorption Spectroscopy
Takeo Watanabe, Yuichi Haruyama, Daiju Shiono*, Kazuya Emura,
Takuro Urayama, Testuo Harada, and Hiroo Kinoshita
Center for EUVL, Laboratory of Advanced Science and Technology for Industry,
University of Hyogo
3-1-2 Kouto, Kamigori, Ako-gun, Hyogo 678-1205, Japan* Tokyo Ohka Kogyo Co., Ltd.
1590 Tabata, Samukawa, Koza, Kanagawa, 253-0114, Japan

It had been reported that tri-phenysulfonium cyclo(1,3-perfluoropropanedisulfone) imidate(TPS-IMIDATE) as a photo acid generator has approximately four times faster sensitive rather
than tri-phenysulfonium perfluorobutanesulfonate (TPS-PFBS) under the EUV exposure. In thispaper, we discussed the differences of the sensitivity and the chemical reaction between
TPS-IMIDATE and TPS-PFBS, on the basis of the EUV-induced analysis of the SR absorption
spectroscopy. From the analysis of the SR absorption spectroscopy, F and C atoms in the anion of
TPS-IMIDATE decomposed rather than that of TPS-PFBS. The sensitivity advantage of
TPS-IMIDATE might own to the anion decomposition reaction. The anion decomposition reaction
might be originated to the photo-excitation of the photoacid generator. The anion of
TPS-IMIDATE decomposed to smaller molecule and the sensitivity becomes higher.
Keyword: EUVL, chemically
amplified resist, photoacid generator,
decomposition of anion of PAG, SR absorption spectroscopy

and ArF lithography. Thus, in order to achieve low
LWR, the yield of the acid should increase. In
addition, to achieve the high sensitivity and the
low LWR, the acid production yield from thephotoacid generators in the chemically amplifies
resist [2-4] should increases.
In focusing, the production acid yield, thechemical reaction analysis on the basis of EUV
photo irradiation should be performed in the basic
study.[5-9]In the previous report, for resist A, the peak at
the absorbance at 1156 cm-1 in the fouriertransform infrared (FT-IR) spectra increased after
EUV exposure.[7-9] However, there was nochange in the FT-IR spectra of resist B before andafter EUV exposure. As a results of the electron
orbital calculation using perturbation theory by thesoftware code Gaussion03 [10], the peak at
approximately 1156 cm-1 in FT-IR spetra of resist
A corresponds to C-F bonding of the anion of

1. Introduction
Extreme ultraviolet lithography (EUVL) [1] is apromising lithographic technology which should
begin to transfer to the production line forsemiconductor electronics from the 25-nm nodearound 2013. The first top issue of EUVL is toachieve the EUV source power of 180 W at theintermediate focus position, when the resist
sensitivity is assumed to be 10 mJ/cm2. If the muchhigher sensitive resist can be performed, the EUV
source power could be relaxed. In addition, thethird issue of EUVL is to develop the EUV resist
which has the sensitivity of 10 mJ/cm2 and the line
width roughness (LWR) of smaller than 2 nm (3V)
because of the trade of relationship between the
resolution, the LWR, and the sensitivity, so called“RLS” trade off. The photon number which
requires for the patterning in EUV isapproximately one order smaller than those in KrF

71

TPS-IMIDATE.
As a result, the outgassing
measurements
and
the
FT-IR
spectrameasurements indicated that the EUV-induced
reaction of TPS-IMIDATE occurred more
efficiently than that of TPS-PFBS. To clarify thedifference of the anion decomposition, the analysis
using SR spectroscopy is performed. This paper
focused on the chemical reaction analysis of themodel chemically amplified resists by the SR
absorption spectroscopy.

Table 1. Model resist material
SampleResist A
Resist B
Resin
n

m

O
O

OH

PAG
O2S
S+ -N
O2S

CF2
CF2

S+ C4F9SO3-

CF2

2.Experimental
Solvent

PGMEA

2.1. Materials
2.3. SR Absorption Experiment
The model resists which were employed inthis study are shown in Table 1. The resists A
and B is employed poly (hydroxystyreneco-t-butylacrylate) as the base polymer, andpropyleneglycol
monomethyletheracetate(PGMEA) as a solvent. Resists A and B
employed triphenylsulfonium cyclo(1,3- perfluoro
propanedisulfone) imidate (TPS-IMIDATE) andtriphenylsulfonium
perfluorobutanesulfonate(TPS-PFBS) as the photoacid generator,
respectively.
The PAG content isapproximately 30 wt% of the base polymer toincrease the detection S/N ratio of the anion
decomposition species from the PAG in the
SR spectroscopy measurement before andafter EUV exposure. The resist solution was
spin coated on a 4-inches silicon wafer to be a
50-nm-thickness. The film thickness wasmeasuredbyNanometrics
6100A(NANOmetrics). The prebake conditions was
carried out on a hot plate at the temperature of
130ºC in the time period of 90 s.

TheSR
absorption
spectroscopy
measurements were performed at the end
station of the BL07B beamline at the
NewSUBARU synchrotron radiation facility.
The short undulator was employed as a lightsource of this beamline. The configuration
setup of the BL07B is shown in Fig.1. The
beamline consists of three glancing mirrossuch as M0, M1 and M2, the monochromater(G), the entrance (S1) and exit (S2) slits andthe end station exposure and analyzing
chambers. The loadlock chamber was adapted
to these chambers to exchange the sample.
The photography of the BL07B beamline andthe end station are shown in Figs.2(a) and 2(b).
The variable line spacing plane gratings(VLSPG) were employed as monochromator.
Three density types such as 600, 1200, and2400 lines/mm were installed in the
monochromator vacuum chamber. The photon
energy region is from 80 eV and 800 eV in theFig. 1 System configuration of the BL07B beamline.

72SR spectroscopy. The exit slit size is 20
Pm(H)20 Pm(V) and the SR light spot sizeon a sample is 1 mm(H)1 mm (V). Theenergy resolution E/ ' E is approximately 1000.
The photon flux of the photon energy of 91.8
eV (O=13.5 nm) is approximately 3.010 11
photons/s/100mA.
The absorption signal was obtained from theratio of the photocurrent from the sample to thephotocurrent from the gold mesh. The total energy
resolution was ᨺ0.5 eV. The photocurrent wasmeasured by the electrometer (6514, Keithley).
For the absorption measurement of F 1s
core level, the measured energy region is685-735 eV and 2400 lines/mm VLSPG was
employed with the undulator gap of 52.0 mm.
For the absorption measurement of C 1s corelevel, the measured energy region is 280-330
eV and 1200 lines/mm VLSPG was employedwith the undulator gap of 48.0 mm. For theabsorption measurement of N 1s core level,
the measured energy region is 390㨪440 eV
and 2400 lines/mm VLSG was employed withthe undulator gap of 51.0 mm. The electron
current generated on the sample is measured
in the SR absorption experiment during theSR light exposure.

3. Results and Discussions
3.1. SR Absorption Spectra
SR absorption spectra of F 1s core level at thephoton-energy ranges of 685-735 eV of resists
A and B are shown in Figs. 3 (a) and 3(b),respectively. For resist A, the absorption at
the photon energy of 697 eV decreased when
the EUV exposure dose increased and theabsorption disappeared at the EUV dose of
104 mJ/cm 2 . For resist B, the absorption at thephoton energy of 697 eV decreased when the
EUV exposure dose increased. However, theabsorption signal remained at the EUV
exposure dose of 104 mJ/cm2 . The EUV
exposure dose dependency of the absorptionof F atoms at the photon energy of 697 eV isshown in Fig. 4. The decomposition of F
atoms in the anion of the TPS-IMIDATE haseasier to decompose than that of TPS- PFBS.
As the results, F atoms decomposition
speed of the TPS-IMIDATE is faster than thatof the TP- PFBS.

a)

a)

b)
b)

Fig. 3 Absorption spectra of F 1s core level in theanions of (a) TPS-IMIDATE and (b) TPS- PFBS.

Fig. 2 Photographs of (a) BL07B beamline and (b) end
station.

73

much higher than that of resist B.
5HVLVW$,QWHQVLW\ DUEXQLW 

S-bondinga)

5HVLVW%

V-bonding







'RVH P-FP 

S-bondingb)Fig. 4 EUV exposure dose dependency of theabsorption of F 1s core level at the photon energyof 697 eV.

Absorption spectra of C 1s core level at thephoton-energy ranges of 280-330 eV of resists
A and B are shown in Figs. 5 (a) and 5(b),respectively.
For resist A, the absorption at the photon
energy of 287 eV had no change. Thus, itmeans that the S-bonding of the benzyl groupof the base polymer has no change. However,
the absorption at the photon energy of 290 eV
decreased after the EUV exposure. It meansthat the anion of the V-bonding of the anion of
TPS-IMIDATE decomposed under the EUV
exposure.
For resist B, the absorption at the photon
energy of 290 eV had no change before andafter the EUV exposure. It means that theanion of the V-bonding of the anion of
TPS-IMIDATE decomposed under the EUV
exposure.
Absorption spectra of N 1s core level at thephoton-energy ranges of 390-440 eV of resist
A is shown in Fig.6. the absorption at thephoton energy of 405 eV decreased under the
EUV exposure. And the photo-energy of 403
eV increased under EUV exposure and thechemical shift was observed. It means that N
atoms in the anion of TPS-IMIDATE
decomposed and reconstructed under the EUV
exposure.
As the results of the SR spectroscopy, theV-bonding of the anion of TPS-IMIDATE
decomposed to the small molecule size andthe acid diffusion length might become large.
Thus the sensitivity of resist A might become

V-bondingFig. 5 Absorption spectra of C 1s core level of theanions of (a) TPS-IMIDATE and (b) TPS- PFBS.

Fig. 6 Absorption spectra of N 1s core level in the
TPS-IMIDATE anion.

4. Conclusion
As the analysis results of the SR
spectroscopy measurement, it was confirmedthat the decomposition reaction begin to occur
by the absorption by the EUV photons at F

74

atoms in the anion of TPS-IMIADTE and theanion molecular size becomes smaller than theoriginal one. However, for resist B, only F
atoms in the anion of TPS-PFBS decomposed
and the molecular size of the anion did not
dramatically change. Since the anion size of
TPS-IMIDATE might be much smaller thanthat of TPS-PFBS, the acid diffusion length inresist A might become larger than that in resist
B.
To achieve the low LWR, it had introduced
generally that the diffusion length of PAG
should decreased by increasing the molecularsize of the anion of PAG. However, for theanion PAG which include F atoms, from theresults of the SR spectroscopy, F atoms might
decompose under EUV exposure. Therefore,
since the anion of the PAG which includes F
atoms should be analyzed carefully if thedecomposition reaction of the anion of PAG
would occur or not.
The SR absorption spectroscopy might be a
powerful analysis method to analyze thedecomposition reaction of the anion of PAG.
To satisfy the specification of the EUV resist
which require for high volume manufacturing,
all the chemical reaction should be taken inaccount.

References
1. H. Kinoshita, K. Kurihara, Y. Ishii and Y.
Torii, J. Vac. Sci. & Technol., B7 (1989) 1648.
2. H. Ito, C. G. Willson, and J. M. J. Frechet,
Digest of Tech. Papers 1982 Symp. VLSI Tech.,(1982) 86.
3. H. Ito and C. G. Willson, Polym. Eng. Sci., 23(1983) 1012.
4. H. Ito, G. Breyta, D. Hofer, R.
Sooriyakumaran, K. Petrillo, and D. Seeger, J.
Photopolym. Sci. Technol., 7 (1994) 433.
5. T. Watanabe, K. Hamamoto, H. Kinoshita, H.
Hada and H. Komano, Jpn. J. Appl. Phys. 43(2004) 3713.
6. H. Hada, T. Watanabe, H. Kinoshita and H.
Komano,”Outgassing Analysis in EUV Resist”
J. Photopolym. Sci. Technol., 18 (2005)
475.
7. T. Watanabe, H. Hada, S. Y. Lee, H. Kinoshita,
K. Hamamoto and H. Komano, Jpn. J. Appl.
Phys., 44 (2005) 5866.
8. Takeo Watanabe, Hideo Hideo, Hiroo
Kinoshita, Yuzuru Tanaka, Hideaki Shiotani,
Yasuyuki Fukushima and Hiroshi Komano,
Proc. SPIE, 6153 (2006) 615343-1.
9. Takeo Watanabe, Hideo Hada, Yasuyuki
Fukushima, Hideaki Shiotani, Hiroo Kinoshita
and Hiroshi Komano, Synchrotron Radiation
Instrumetation: Ninth International Conference,
AIP 879 (2007) 1470.
10. Gaussian03 electron orbital calculation
softwareisinformedin
URL:http://www.gaussian.com/home.htm.

75

Plasma-Debris Sputter Resistant X-ray Mirror
S. Amano, T.Inoue, T.Harada
LASTI/UH
Abstract
A diamond-like carbon (DLC) mirror, used as a grazing incident mirror in a plasma X-ray source,
exhibits a high resistance to plasma debris sputtering. The erosion rate due to plasma debris
sputtered at the incident debris angle of 20° was measured using a laser-produced Xe plasma
source developed by the authors. The results indicate that the DLC film has a 5- and 15-fold higher
sputtering resistance compared to films made of the traditional mirror materials Ru and Au,
respectively. Because the DLC mirror retains a high sputtering resistance to Sn ions, it may beeffective in Sn plasma source applications. We conclude that a grazing incident X-ray mirror
coated with DLC can be of use as a plasma debris sputtering resistant mirror.
Plasma X-ray sources, which produce radiationfrom laser-produced plasmas (LPP) or dischargeproduced plasmas (DPP), find use in various
industrial applications. However, along with Xrays, the plasmas in these sources emit debris
consisting of ions, neutral atoms, various
fragments, vapor and so forth. Such debris
damages mirrors located near the plasma, quickly
degrading their reflectivity. Because the amountof plasma debris increases in proportion to the Xray generating power, the debris problem is a
critical issue in high-power plasma sources forindustrial applications. We propose a new
approach to mitigate debris effects in plasma Xray sources, namely the use of debris resistantmirrors that suffer reduced debris damage ascompared with traditional mirrors.
In our lab, we developed a laser-produced plasma
X-ray source (LPX), which employs a solid Xetarget. This device has demonstrated continuous
X-ray generation at 5–17 nm with an average
power of 20 W. A diamond-like carbon (DLC)
coating, also developed in our laboratory, wasdeemed a good candidate for the mirror material,owing to its high hardness. In this work, wemeasured the erosion rate due to debris sputteringin the plasma source. The results were comparedwith similar experiments with mirrors coated with
Ru and Au films, which are typically used as
mirror coating materials.
The LPX consists of a system that supplies a solid
Xe-target and a drive laser. The target supply
system comprises a cylindrical drum filled withliquid nitrogen, so its copper surface is at liquid
nitrogen temperature. Xe gas blown onto thissurface condenses to form a solid Xe layer. The
solid Xe layer-coated drum rotates about thevertical axis, simultaneously moving up anddown vertically during rotation. The resultant
spiral motion ensures that a fresh target surface iscontinuously supplied for every laser shot. The
drive laser is a slab laser with an average powerof 100 W and a pulse repetition rate of 320 Hz.
The laser pulses (λ = 1064 nm) with a pulse widthof 20 ns are focused on the solid Xe-target,
continuously producing plasma.
We used a quartz crystal microbalance (QCM) tomeasure the erosion rate of the DLC films after
sputtering with Xe plasma debris from the LPX.
As such debris bombards a test film that is coatedonto the QCM, atoms are ejected from the surfaceof the film, changing the resonant frequency of
the QCM. Mass loss in the film can be deduced
from this frequency change, and erosion rates ofthe film can be calculated directly. The
experimental setup is shown in Fig.1.

Figure 1. Experimental setup.
The drum target system and the QCM were
installed in a vacuum chamber (pressure of 0.2Pa),
while drive laser pulses coming through awindow were focused perpendicularly onto thetarget by a lens. The coated QCM was placed 73
mm from the plasma at a 45° angle with respect
to the incident laser beam. Its sensor surface wastilted at a 20° angle with respect to the incident
debris axis, thus forming a grazing incidence
mirror. Test films coated on the quartz sensors
consisted of DLC, Ru and Au, with a coating
thickness of 500, 100, and 100 nm, respectively.
After laser irradiation of the films for 2–10 min at
320 Hz, we used the QCM to monitor total
erosion rates during extended multi-shot plasma
operation.

76

The measured erosion rates of the DLC, Ru andAu films at an incident debris angle of 20° areshown in Fig. 2. We see a decreased erosion ratewith increasing binding energy, and the erosion
rate ratio is DLC : Ru : Au = 1 : 5 : 15. We also
performed an erosion calculation using the SRIM
software. SRIM can calculate a sputtering yield
Ysputt for normal carbon, Ru and Au. For a given
sputtering yield Ysputt (atoms / ion) and an ion flux
Fion (ions), the erosion rate of a mirror film ΔT(cm / shot) can be written as:m
ΔT = Y sputt ⋅ Fion ⋅ρ,Sn DPP X-ray sources are currently used as
extreme ultraviolet lithography (EUVL) sourcesin the industrial mass production ofsemiconductors. These sources emit X-rays at awavelength of 13.5nm, and employ grazing
incidence Ru mirrors. As shown in Fig.3, the
DLC sputtering yield by Sn ions is similar to theone by Xe ions, as calculated by the SRIM code.
Therefore, a DLC mirror may also be resistant toSn sputtering. Of course, because the Sn plasma
debris includes both “deposition“ and “sputter”
types of particles, additional debris mitigation
techniques are necessary. However, we predictthat a DLC mirror will enjoy a longer lifetime in a
Sn plasma source.

where m is the mirror mass (g) and ρ is themirror density (g/cm2).
The plasma debris emitted from the LPX was€studied in detail previously, with the results
indicating the debris predominantly consists offast ions. The time of flight (TOF) Xe ion signal
as detected by a Faraday-cup indicated the ion
energy is less than 6 keV, and the ion flux at the
QCM was calculated to be about 6 × 1011 /shot.
Using this result as the ion flux Fion and thecalculated sputtering yield Ysputt in the eq., we canpredict the erosion rates ΔT for the three films.
The ratios of these calculated values are C : Ru :Au = 2 : 6 : 16 , which are close to theexperimental results of 1 : 5 : 15. Compared withthe calculated erosion rate for C, the measured
value for the DLC is slightly smaller. Thisdifference may be due to the different types ofcarbon involved: high hardness DLC in theexperiment vs. normal carbon (graphite) in thecalculation.

Figure 3. DLC sputtering yield by Xe and Sn ions,calculated with the SRIM code.

References[1] S.Amano et al., Appl. Opt., 52, pp.3845(2013).

Figure 2. Erosion rate of the DLC, Ru, and Au
films as measured by QCM with a debris
incidence angle of 20°.

77

Electronic Structure of the Fluorinated Self-Assemble
Monolayer by Photoemission and Absorption Spectroscopy
Yuichi Haruyama, Makoto Okada, and Shinji Matsui
Laboratory of Advanced Science and Technology for Industry, University of Hyogo
Abstract
The electronic structure of F-SAMs (fluorinated self-assembled monolayer) thin films withdifferent chain length was investigated by the photoelectron and absorption spectroscopy. The
photoelectron spectra in the wide region and in the C 1s core-level region were measured and thechemical compositions and components of the photoelectron spectra F-SAMs thin films withdifferent chain length were clarified. In addition, the C K-edge absorption spectra of F-SAMs
thin films were measured and the several spectral features in absorption spectra of the F-SAMs
thin films were assigned. Based on the results of the photoelectron and absorption spectroscopy
measurements of four kinds of F-SAMs with different chain length, the electronic structure of the
F-SAMs thin films is discussed.
Introduction
The study of nanoimprint lithography (NIL) [1-2] has attracted much attention for many industrial field
because it is a promising method to fabricate various nanostructures with a low cost and a high throughput. In
the process of NIL, the mold is usually coated with an antisticking layer to avoid resist adhesion. As anantisticking layer of nanoimprint mold, the fluorinated self-assemble monolayer (F-SAM) is used, forexample. The evaluation of the F-SAM with different chain length is one of the critical issues in NIL [3]. In
this study, four kinds of F-SAMs with different chain length were evaluated using the photoemission and theabsorption spectroscopy.

Figure 1. Four kinds of F-SAM thin films withdifferent chain length.

F 1s
FAS17

Intensity (arb. units)Experiments
Four kinds of F-SAMs were prepared from aprecursor [CF3(CF2)n(CH2)2Si(OCH3)3; n=0, 3, 5,
and 7] as denoted FAS-3, 9, 13, and 17,
respectively. All photoelectron and absorption
measurements were performed on a BL7B end
station at the NewSUBARU facility, University of
Hyogo. The photoelectron spectra were measured
in an analysis chamber mounted with ahemispherical electrostatic spectrometer (VSW
Ltd, CL150). The synchrotron radiation and the
Mg Kα line were used as the excitation source
and were incident at 45° with respect to thesurface normal. The total energy resolutions wereabout 0.7 eV for the C 1s core-level regions. Goldfilms evaporated on copper sample holders and
F-SAMs were used for the Fermi levelmeasurements and the total energy resolution
reference. Absorption spectra were measured by
the total electron yield method. The total energy
resolution was about 0.5 eV. The photocurrents
from the sample and from a gold mesh wererecorded simultaneously. The absorption signal
was obtained from the ratio of the photocurrent
from the sample to the photocurrent from the gold
mesh.

Si 2p
C 1s

Si 2s

FAS13
FAS9
FAS3
Si
C(KLL)
1000

Results
Figure 2 shows the photoelectron spectra infour kinds of F-SAMs with different chain length.
The photoelectron spectrum of Si substrate is alsoplotted for comparison. Several peaks wereobserved at ~688, ~532, ~290, ~100eV, which

F(KLL)
O 1s

800

400
600
Binding energy (eV)200

0Figure 2. Wide scan of the photoelectron spectra of
the four kinds of F-SAMs thin films with different
chain length. The photoelectron spectra in thisfigure were normalized by the C 1s peak intensity.

78

were originated from the F 1s, O 1s, C 1s, and Si 2p electrons, respectively. With increasing the chain length,
the intensity of the peak at ~688eV increased while intensity of the peaks at ~532 and ~100eV decreased. On
the other hand, the intensity of the peaks at ~ 290 eV did not change with increasing the chain length. These
indicate that the intensity of the Si substrate decreased due to the increase of thickness of F-SAM withincreasing the chain length. In Figure 3, the photoelectron spectra of the C 1s core-level region in four kindsof F-SAMs with different chain length are plotted. In the photoelectron spectra of the C 1s core-level, threepeaks at ~293, ~286, and ~284.5 eV were observed in the FAS-3 although four peaks at ~293, ~291, ~286,
and ~284.5 eV were observed in the FAS-9, 13, and 17. The intensity of the peak at 291 eV increased withincreasing the chain length. On the other hand, the intensity of the peaks at ~293, ~286 eV did not changewith increasing the chain length. From the chemical compositions of four kinds of F-SAMs with different
chain length, these peaks at ~293, ~291, ~286, and ~284.5 eV were assigned to the CF3, CF2, CH, and C-C
components, respectively. Figure 4 shows the absorption spectra in four kinds of F-SAMs with different
chain length. Several peaks were observed at 285, 292, 295, 296-300eV. The intensity of the peak at 292eV
increased with increasing the chain length. On the other hand, the intensity of the peaks at 285, 295,
296-300eV did not change with increasing the chain length. The peaks at 292 eV were assigned to theσ*(C-F) and σ(CF2) componetns. On the other hand, these peaks at 285, 295, and 296-300 eV were assigned
to the π*(C-C) and σ*(C-H), σ*(C-F) and π(CF3), and σ*(C-F), σ(CF2, CF3), σ*(C-C) components,
respectively [4]. When the incident angle of the synchrotron radiation to the sample surface was changed, noclear change of the absorption spectra was not observed in four kinds of F-SAMs with different chain length.
This indicates that each molecular with different chain length on the Si surface seems to be oriented
randomly.
C 1s

90

C K-edge

FAS-17

Intensity (arb. units)

Intensity (arb. units)

FAS17
FAS13
FAS9
FAS3

o

FAS-13
FAS-9
FAS-3

Si
295

290
285
Binding energy (eV)

280

280

Figure 3. Photoelectron spectra of the C 1s
core-level region in four kinds of F-SAMs thinfilms with different chain length.

290

300
310
Photon energy (eV)320

Figure 4. C K-edge absorption spectra in fourkinds of F-SAMs with different chain length.

References[1] S. Y. Chou, P. R. Krauss, P. J. Renstrom, Appl. Phys. Letters 67, 3114-3116 (1995).
[2] K. Nakamatsu, K. Watanabe, K. Tone, H. Namatsu, and S. Matsui, J. Vac. Sci. Techmol. B 23, 507-512(2005).
[3] Y. Nakai, S. Omoto, M. Okada, K. Kanda, Y. Haruyama, and S. Matsui, J. Photopolymer Sci. and Tech.,23, 55-58 (2010).
[4] I. Ishii, R. McLaren, A. P. Hitchcock, K. D. Jordan, Y. Choi, M. B. Robin, CAN. J. Chem., 66, pp. 2104
(1988).

79

Orientation evaluation of 3D-photoreactive liquid
crystalline polymer structure fabricatedby thermal nanoimprinting
Makoto Okada1, Emi Nishioka2, Risa Hosoda2, Mizuho Kondo2, Yuichi Haruyama1,
Tomoyuki Sasaki3, Hiroshi Ono3, Nobuhiro Kawatsuki2 and Shinji Matsui1
1

2

Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Japan
Department of Materials Science and Chemistry, Graduate School of Engineering, Univ. of Hyogo,3
Department of Electrical Engineering, Nagaoka University of Technology
Abstract

Photoreactive liquid crystalline polymer is able to be control by linearly polarized ultra violet(LPUV) irradiation and heat treatment. We found that P6CAM, which is one of the photoreactive
liquid crystalline polymers, was reoriented by thermal nanoimprinting. It is confirmed that theP6CAM molecules were reoriented parallel to the imprinted line. To examine whether the twomolecular orientation directions are induced on the P6CAM film, we carried out thermal
nanoimprinting using a mold with 3D structure pattern. As the results, the P6CAM 3D structure
has two molecular orientation directions.
Introduction.
The photo-induced orientation of polymericfilms has received much attention due to its
potential use in many kinds of optical andphotonics applications. P6CAM, which is a one ofthe photoreactive liquid crystalline polymers,
exhibits a large photoinduced molecularreorientation with a high photoreactivity toward
linearly polarized UV (LPUV) light and heat
treatment [1, 2]. We found that P6CAM wasaligned by thermal nanoimprinting[3] using line
and space (L&S) pattern mold [4]. We confirmedthat the P6CAM molecules were reoriented
parallel to the imprinted line on the imprinted
P6CAM film in the case of using a normal L&S
pattern mold. If a mold with bidirectional L&S
pattern is used for the thermal nanoimprint on the
P6CAM, two reorientation directions of themolecules according to the bidirectional moldpattern may be induced. To confirm that, wefabricated the bidirectional line pattern mold byelectron beam (EB) lithography and reactive ion
etching (RIE) and then carried out thermal
nanoimprinting using this mold on the P6CAM
film on a glass substrate, subsequently evaluatedthe molecular orientation by measuring thediffraction efficiency.

mold was coated with an antisticking layer. We
used a thin polydimethylsiloxane (PDMS) layer
as the antisticking layer [5]. We carried out
thermal nanoimprinting using this mold.

Fig. 1 Illustration of bidirectional line pattern.
The P6CAM was spin-coated on the glass
substrate. The mold and P6CAM substrate were
heated by 165 C during thermal nanoimprinting.
The imprinting pressure and pressing time were
15 MPa and 4 min, respectively. After thermal
nanoimprinting, we observed the fabricated
P6CAM structure by POM under crossed-nicols
and atomic force microscopy (AFM), as shown in
Fig. 2. The POM image showed the patterncontrast which means the molecular orientation
related the pattern configuration. In addition, the3D structure was successfully imprinted on
P6CAM, as shown in Fig. 2(b).

Fabrication of bidirectional line pattern on
P6CAM
Figure 1 shows the illustration of bidirectionalline pattern. The linewidth was 2 m. The line
heights were 200 and 100 nm. The two line
patterns crossed each other at right angles. The

(a)

(b)

Fig. 2 (a) POM and (b) AFM images of fabricated
3D-P6CAM structure.

80Evaluation of molecular orientation of
imprinted P6CAM-3D-structure
We examined the orientation direction of the
P6CAM 3D structure by measuring the diffraction
efficiencies using linearly polarized (LP) 633-nm
light from 0 to 180. If the P6CAM is reoriented
by thermal nanoimprinting, the diffraction
efficiency depend on the rotation angle of theincident LP light.

1st-order diffraction efficiency is highest. Figure3(b) plots the 0th and 1st-order diffraction
efficiencies of the P6CAM 3D structure as afunction of the incident polarization angle. The
diffraction efficiency depend on the rotation angleof the incident LP light. In addition, thediffraction efficiency of the 1st-order diffracted
light of the 200 nm-height-line pattern was thehighest at 0 and the lowest at 90. In contrast,that of the 100 nm-height line pattern was thelowest at 0 and the highest at 90. These results
indicates that the P6CAM was reoriented parallel
to each line.
Conclusion
We carried out thermal nanoimprinting using
the bidirectional line pattern mold and evaluatedthe orientation of the fabricated P6CAM 3D
structure. The P6CAM 3D structure was
successfully fabricated by thermal nanoimprinting.
In addition, the P6CAM 3D structure has twomolecular orientation directions and thereorientation direction was parallel to the line.
This means that we are able to arbitrarily control
the P6CAM molecular orientation by thermal
nanoimprinting.

(a)Acknowledgements
This work was partially supported by theJapanese Ministry of Education, Culture, Sports,
Science and Technology (MEXT), Grant-in-aid
for Scientific Research on Innovative Areas ''Emergence in Chemistry'' (20111013).

(b)
Fig. 3 (a) Relationship between directions ofincident LP light and imprinted lines in the
optical measurement. (b) Diffraction efficiencies
of P6CAM 3D structure.
Figure 3(a) shows the relationship between
directions of incident LP light and imprinted lines
in the optical measurement. When the rotation
angle of incident LP light was 0, the LP light
direction is parallel to the 200 nm-height-line
pattern. At 90, the LP light direction isperpendicularly to the 200 nm-height-line. On theother hand, in the case of the 100 nm-height line
pattern, the LP light directions at 0 and 90 areperpendicularly and parallel to the line pattern,
respectively. When the P6CAM orientation andincident LP light directions are the same, theReferences[1] E. Uchida and N. Kawatsuki:
Macromolecules. 39 (2006) 9357.
[2] N. Kawatsuki, T. Kawanishi, and E.
Uchida: Macromolecules 41 (2008) 4642.
[3] S. Y. Chou, P. R. Krauss, and P. J.
Renstrom: Appl. Phys. Lett. 67 (1995) 3114.
[4] M. Okada, et al.: Jpn. J. Appl. Phys. 49(2010) 128004.
[5] M. Okada, et al.: J. Vac. Sci. Technol. B 29
(2011) 06FC09.

81

82

List of Publications

List of publications(1) Papers
1.

D. Li, M. Hangyo, Y. Tsunawaki, Z. Yang, Y. Wei, S. Miyamoto, M. R. Asakawa, and K.
Imasaki,“Growth rate and start current in Smith–Purcell free-electron lasers”, Appl. Phys. Lett.
100, 191101-1-3(2012).

2.

D. Li, M. Hangyo, Y. Tsunawaki, Z. Yang, Y. Wei, S. Miyamoto, M. R. Asakawa and K.
Imasaki, “Theoretical Analysis on Smith-Purcell Free-Electron Laser”,"Free Electron

Lasers", Edited by Sándro Varró,INTECHWEB.ORG, Janeza Trdine 9, 51000 Rijeka, Croatia,
March 2012, ISBN:978-953-51-0279-3. Chapter 6, pp151-174 (2012).

3.

Tomoaki Inoue, Takayasu Mochizuki, Shuji Miyamoto, Kazuya Masuda, Sho Amano, andKazuhiro Kanda, “Characteristics of a Cylindrical Collector Mirror for Laser^Produced Xenon
Plasma Soft X-Rays and Improvement of Mirror Lifetime by Buffer Gas”,Review of Scientific
Instruments, v.83, no.12, 123110-15 (2012).

4.

S.Amano, T,Inoue, “Laser-plasma extreme-ultraviolet source at 6.7nm using a rotating
cryogenic Xe target”, Applied Physics B, Vol.108, 743-747(2012)

5.

Hideki Kido, Tomoyuki Kuroki, Masaaki Okubo, Yuichi Utsumi, “Application of photo-etchingof polytetrafluoroethylene induced by high energy synchrotron radiation to LIGA”,
Microsystem Technologies, 19, 3, 301-307, (2013)

6.

Ryo Takahashi, Takao Fukuoka, Yuichi Utsumi, and Akinobu Yamaguchi, “Optofluidic Devices
with Surface-Enhanced Raman Scattering Active Three- Dimensional Gold Nanostructure”,
Japanese Journal of Applied Physics, in press, (2013)7.

池内裕章，岸原充佳，内海裕一，河合正，太田勲，“放射光直接エッチングによるテフ
ロン導波管横断回路の設計と試作”，電子情報通信学会論文誌(C), vol.J95-C, no.12,
pp.531-534, Dec. 20128.

Yasuharu Ohgoe, Kenji K. Hirakuri, Hidetoshi Saitoh, Takahiro Nakahigashi, Naoto Ohtake,Atsushi, Hirata, Kazuhiro Kanda, Masanori Hiratsuka, Yasuhiro Fukui,

83“Classification

of DLC films in terms of biological response”, Surface & Coatings Technology, 207,
350-354 (2012)9.

Tomoaki Inoue, Takayasu Mochizuki, Kazuya Masuda, Sho Amano, Tsugushima Sekioka,
Kazuhiro Kanda, “Effective collision cross section of xenon plasma debris in argon buffergas”, J. Phys. B: At. Mol. Opt. Phys, 45, 115401 (2012)

10. Akihiro Fujimoto, Makoto Okada, Yuji Kang, Masahito Niibe, Shinji Matsui,Kanda, Tsuneo
Suzuki,and Kazuhiro Kanda, “Effective collision cross section of xenon plasma debris inargon buffer gas”, Jpn. J. Appl. Phys., 51, 06FD07 (2012)

11. Akira Wada, Katsuaki Koshimura, Masahito Niibe, Hidetoshi Saitoh, Kazuhiro Kanda,andHaruhiko Ito, “Carbon-K NEXAFS measurements of a-CNx films formed fromdecomposition of BrCN in electron cyclotron resonance plasma of He, Ne, and Ar”,
Journal of Non-Crystalline Solids, 358, 124-128 (2012)

12. Takeo Watanabe, Yuichi Haruyama, Daiju Shiono, Kazuya Emura, Takuro Urayama, Tetsuo
Harada, and Hiroo Kinoshita, "Chemical Reaction Analysis of EUV CA Resist using SR
Absorption Spectroscopy," J. Photopolymer Sci. Technol 25, 569, 2012.

13. Yukiko Kikuchi, Eishi Shiobara, Hiroyuki Tanaka, Isamu Takagi, Kazuhiro Katayama,
Norihiko Sugie, Toshiya Takahashi, Soichi Inoue, Tekeo Watanabe, Tetsuo Harada, andHiroo Kinoshita, Study of EUV outgassing spatial distribution toward witness plate in the
EUV outgas tester, SPIE Proc. 8679, 86790M, 2012.

14. Mitsunori Toyoda, Kenjiro Yamasoe, Tadashi Hatano, Mihiro Yanagihara, Akifumi
Tokimasa, Tetsuo Harada, Takeo Watanabe, and Hiroo Kinoshita, At-Wavelength Extreme
Ultraviolet Lithography Mask Observation Using a High-Magnification Objective withThree Multilayer Mirrors, Appl. Phys. Exp. 5, 112501, 2012.
15. Yutaka Nagata, Tetsuo Harada, Masato Nakasuji, Hiroo Kinoshita, Katsumi Midorikawa,“Development of highly spatial-coherent, 13.5-nm high-order harmonics for EUVL mask
inspection using coherent EUV scatterometry microscope”, IEEE, Photonics Conference
Proceeding, 935-936, (2012).

16. Tetsuo Harada, Masato Nakasuji, Takeo Watanabe, Yutaka Nagata, Hiroo Kinoshita,84

Developmentofstandalone

coherent

EUV

scatterometry

microscopewithhigh-harmonic-generation EUV source, SPIE Proc. 8441, 8441-2, 2012. (invited paper)

17. Masato Nakasuji, Akifumi Tokimasa, Tetsuo Harada, Yutaka Nagata, Takeo Watanabe,
Katsumi Midorikawa, Hiroo Kinoshita, Development of Coherent Extreme-Ultraviolet
Scatterometry

MicroscopewithHigh-Order

Harmonic

Generation

Sourcefor

Extreme-Ultraviolet Mask Inspection and Metrology, Jpn. J. Appl. Phys. 51, 06FB09, 2012.
18. Tetsuo Harada, Masato Nakasuji, Akifumi Tokimasa, Takeo Watanabe, Youichi Usui, andHiroo Kinoshita, Defect Characterization of an Extreme-Ultraviolet Mask Using a Coherent
Extreme-Ultraviolet Scatterometry Microscope, Jpn. J. Appl. Phys. 51, 06FB08, 2012.
19. 村松康司，潰田明信，原田哲男，木下博雄，ニュースバル多目的ビームライン BL-10における軟Ｘ線吸収分析（１）；分光特性評価と軽元素標準仕様の XANES 測定，Ｘ
線分析の進歩 第 43 集，407, 2012. (in Japanese)
20. 渡邊健夫，原田哲男，木下博雄，「EUV リソグラフィ研究開発センターにおけるリソグラフィ開発」，クリーンテクノロジー2012 年 6 月号, 2012. (in Japanese)
21. Toshiya Takahashi, Norihiko Sugie, Kazuhiro Katayama, Isamu Takagi, Yukiko Kikuchi,
Eishi Shiobara, Hiroyuki Tanaka, Soichi Inoue, Takeo Watanabe, Tetsuo Harada, and Hiroo
Kinoshita, Resist outgassing characterization for qualification in high power EUV
Lithography, SPIE Proc. 8322, 83221E, 2012.
22. 木下博雄, 「ナノデバイス量産に向けた極端紫外線リソグラフィ技術の開発」, 応用物理
81, pp. 391-395, 2012. (in Japanese)

23. M. Okada, M. Iwasa, H. Hiroshima, Y. Haruyama, K. Kanda, and S. Matsui, “Adhesion andfrictional force measurements employing scanning probe microscopy in a pentafluoropropane
gas atmosphere”, J. Vac. Sci. Technol. B 30, 011601-3, 2012

24. S. Iyoshi, M. Okada, T. Katase, K. Tone, K. Kobayashi, S. Kaneko, Y. Haruyama, M. Nakagawa,
H. Hiroshima, and S. Matsui, “Step and Repeat Ultraviolet Nanoimprinting under
Pentafluoropropane Gas Ambient”, Jpn. J. Appl. Phys. 51, 06FJ08-6, 2012

25. K Kanda, T Hasegawa, M Uemura, M Niibe, Y Haruyama, M. Motoyama, K Amemiya, S

85

Fukushima, and T Ohta, “Construction of a Wide-range High-resolution Beamline BL05 in
NewSUBARU for Soft X-ray Spectroscopic Analysis on Industrial Materials”, Journal of
Physics: Conference Series 425, 132005, 2013

26. Masahito Niibe, Takuya Kotaka, Tohru Mitamura, ”Investigation of analyzing depth of N-K
absorption spectra measured using TEY and TFY method”, J. Phys.: Conf. Series, 425, 132008(2013).

27. Masahito Niibe, Keigo Koida, Yukinobu Kakutani: ”Contamination expreiments for Mo/Si
multilayer mirrors with the use of single-bunch synchrotron radiation”, J. Phys.: Conf. Series,
425, 132021 (2013).

28. M. Niibe, K. Sano, T. Kotaka, R. Kawakami, K. Tominaga, Y. Nakano: ”Etching Damage and
Its Recovery by Soft X-ray Irradiation Observed in Soft X-ray Absorption Spectra of TiO2 ThinFilm”, J. Appl. Phys., 113, 126101 (2013).

29. S. Hori, M. Niibe, T. Kotaka, K. Fujii, K. Yoshiki, T. Namazu and S. Inoue, ”X-ray Absorption
Studies on the Growth Process of RF Magnetron Sputtered BN Films: Bias Voltage andSubstrate Temperature Effects”, Jpn. J. Appl. Phys., 52, 045602 (2013).

30. M. Niibe, T. Kotaka, R. Kawakami, Y. Nakano, T. Inaoka, K. Tominaga, T. Mukai, ”Damage
Analysis of n-GaN Crystal Etched with He and N2 Plasmas”, Jpn. J. Appl. Phys. 52, 01AF04(2013). Ranked in the Top 20 Most Downloaded Articles in JJAP (February 2013).

31. Y. Nakano, K. Nakamura, M. Niibe, R. Kawakami, N. Ito, T. Kotaka, K. Tominaga, ”Effect of
UV Irradiation on Ar-Plasma Etching Characteristics of GaN”, ECS J. Solid State Sci. &Technol., 2, 110-113 (2013).

32. R. Kawakami, A. Takeichi, M. Niibe, M. Konishi, Y. Mori, T. Kotaka, T. Inaoka, K. Tominaga,
T. Mukai: ”Capacitively coupled radio frequency nitrogen plasma etch damage to N-typegallium nitride”, Vacuum 87, 136-140 (2013).

33. S. Honda, S. Nanba, Y. Hasegawa, Y. Nosho, A. Tsukagoshi, M. Niibe, M. Terasawa, R. Hirase,
H. Izumi, H. Yoshioka, K-Y. Lee, K. Niwase, E. Taguchi, M. Oura, ”Defect Evolution in
Multiwalled Carbon Nanotube Films Irradiated by Ar Ions” Jpn. J. Appl. Phys., 51 110202(2012).

8634. R. Kawakami, M. Niibe, A. Takeichi, Y. Mori, M. Konishi, T. Kotaka, F. Matsunaga, T.
Takasaki, T. Kitano, T. Miyazaki, T. Inaoka, K. Tominaga: ”Characteristics of TiO2 Thin Film
Surfaces Treated by Helium and Air Dielectric Barrier Discharge Plasma”, Jpn. J. Appl. Phys.
51, 08HB04 (2012).

(2)International Meetings
1. Yoshihiro ASANO, Shuji MIYAMOTO, and LEPS-II collaboration, "Shielding Design of Laser
Electron Photon Beamlines at SPring-8", "12th International Conference on Radiation
Shielding(ICRS-12) & Topical Meeting of RPS Division of American Nuclear Society(RPSD-2012)", September 2-7, 2012, Nara Prefectural New Public Hall, Nara, Japan

2.

Shuji Miyamoto, "Gamma-ray Beambeamline on NewSUBARU" , "Science and Technology
with MeV Photons at Canadian Light Source", Uiv. of Saskatuwan, Jan. 18-19 (2013).

3.

S.Amano, and T.Inoue, “Diamond-Like Carbon Sputtering by Laser Produced Xe Plasma”,8th
International Symposium on Swift Heavy Ions in Matter (SHIM2012), Kyoto, Oct.24-27, 2012.

4.

T.Sekioka, S.Amano, T.Inoue, and T.Mochizuki, “Characteristics of Fast Ions from
Laser-Induced Plasma and their Applicability to Shallow Junction Doping”8th International
Symposium on Swift Heavy Ions in Matter (SHIM2012), Kyoto, Oct.24-27, 2012.

5.

Hiroki Nose, Masaki Ishizawa, Kazuhisa Kuroda, Takeshi Kunisada, Masatoshi Kataoka,
Yuichi Utsumi, “Blood separation chip for automated biological analysis”, RSC(Royal Societyof Chemistry) Tokyo International Conference, pp12, September 6-7 (2012), Chiba, Japan

6.

Ryo Takahashi, Takao Fukuoka, Yuichi Utsumi, “ERS Active Self-assembled Nanostructures
toward Higher Dimension III: Sterically-bulky Self Assembles Array”, RSC(Royal Society ofChemistry) Tokyo International Conference, p12, September 6-7 (2012), Chiba, Japan

7.

Takao Fukuoka, Ryo Takahashi, Yuichi Utsumi, Motofumi Suzuki, “SERS Active
Self-assembled Nanostructures toward Higher Dimension II : Physically Self-assembled
Nanoparticles Array”, RSC(Royal Society of Chemistry) Tokyo International Conference, p11,
September 6-7 (2012), Chiba, Japan

87

8.

Ryo Takahashi, Takao Fukuoka, Yuichi Utsumi, “Three Dimensional Gold Nanostructure for
Plasmonic Sensing”, Gold Science Technology and its Applications, the 6th International
Conference, 2P-043, September 5-8 (2012), Tokyo, Japan

9.

Yuji Yoritama, T. Uchiyama , Akinobu Yamaguchi, Yuichi Utsumi, “Fabrication of Integrated
Magneto Impedance Sensor for Medical Monitoring”, 38th International Conference on Microand Nano Engineering (MNE2012) , p298-378, September 16-20 (2012), Toulouse, France

10. Masaki Ishizawa, Yuichi Utsumi, “Contamination-Free Internally-Triggered Automatic Flow
Sequencing for Microfluidics”, 38th International Conference on Micro and Nano Engineering(MNE2012) , p338-313, September 16-20 (2012), Toulouse, France

11. Hideki Kido, Yuichi Utsumi, Toshihiko Asami, Hajime Mita, “Fabrication of fluorocarbon
resin micro fluidic chip for processing of amino acid derivatization” , 38th International
Conference on Micro and Nano Engineering (MNE2012), p342-339, September 16-20 (2012),
Toulouse, France

12. Ryo Takahashi, Takao Fukuoka, Yuichi Utsumi, “SERS Active Three Dimensional Gold
Nanostructure Fabrication for Optofluidic Device” , 38th International Conference on Microand Nano Engineering (MNE2012), p343-346, September 16-20 (2012), Toulouse, France

13. Ryo Takahashi, Mitsuhiro Yoshida, Yuichi Utsumi, “Single Molecule Detection Using
Sterically-bulky Self Assembles of Gold Nanoparticles”, 38th International Conference on
Micro and Nano Engineering (MNE2012), p123-546, September 16-20 (2012), Toulouse,
France

14. Tsunemasa Saiki, Yasuto Arisue, Kei Kuramoto, Hiroo Shizuka, Masahiro Takeo, Kazusuke
Maenaka, Yuichi Utsumi, “Direction Control of Powder Transport on Solid Substrate by Drive
Frequency of Surface Acoustic Wave Actuator”, 38th International Conference on Micro andNano Engineering (MNE2012), p279-022, September 16-20 (2012), Toulouse, France

15. Yoshiaki Ukita, Takayuki Oguro, Masaki Ishizawa, Hiroki Nose, Yuichi Utsumi, Yuzuru
Takamura, “Visualization of Biological Fluid Behaviour on Spinning Centrifugal Microfluidics
using Coaxial Micro-Stroboscope” 38th International Conference on Micro and Nano
Engineering (MNE2012), p398-304, September 16-20 (2012), Toulouse, France8816. Y. Kang, R. Takahashi, T. Fukuoka, Y. Utsumi, Y. Haruyama, and S. Matsui, “Self-assemblyof gold nanoparticles using imprinted HSQ pattern for SERS measuremen”, 11th International
Conference on Nanoimprint and Nanoprint Technology (NNT12), October 24-26, Napa, USA

17. Masahiro Takeo, Isao Kawaji, Akihiro Nakasuji, Takaaki Tone, Yoshiaki Ukita, Dai-ichiro
Kato, Seiji Negoro, Shinichi Yusa, Makoto Katayama, Yuichi Utsumi, “Automatic ELISA
Analytical System for a Trace Amount of Environmental Chemicals Using A 3-Dimensional
Microreactor with a Novel Antigen-Bound Microfilter”, 16th International Conference on
Miniaturized Systems for Chemistry and Life Science (μTAS), p1192-1164, October 28November 1 (2012), Okinawa, Japan

18. Yoshiaki Ukita, Masaki Ishizawa, Yuzuru Takamura, Yuichi Utsumi, “Internally Triggerd
Multistep Flow Sequencers Using Clepsydra”, 16th International Conference on Miniaturized
Systems for Chemistry and Life Science (μTAS), p1465-1467, October 28- November 1 (2012),
Okinawa, Japan

19. Kyuya Nakagawa, Akihiro Tamura, Yuki Goto, Masahiro Takeo, Yuichi Utsumi, “Preparation ofFreeze-Dried Porous Media in a Microchannel: A New Platform for Enzymatic Reactions”,
16th International Conference on Miniaturized Systems for Chemistry and Life Science (μTAS),
p1765-1767, October 28- November 1 (2012), Okinawa, Japan

20. Hideki Kido, Ikuo Okada, Yuichi Utsumi, Toshihiko Asami, Hajime Mita, “Fabrication of
PTFE micro fluidic chip for processing of amino acid derivatization”, 25th International
Microprocesses

andNanotechnology

Conference(MNC2012),

2P-11-91,

October

30-Nobember 2 (2012), Kobe, Japan

21. Yasuto Arisue, Tsunemasa Saiki, Kei Kuramoto, Yutaka Hata, Hiroo Shizuka, Kazusuke
Maenaka, Yuichi Utsumi, “Proposal of Particle Size Sorting Method by Surface Acoustic
Wave”, 25th International Microprocesses and Nanotechnology Conference (MNC2012),
2P-11-96, October 30-Nobember 2 (2012), Kobe, Japan

22. Masaki Ishizawa, Yuichi Utsumi, “Clepsydra-based Autonomous Flow Sequencer with Liquid
Trap Reservoir”, 25th International Microprocesses and Nanotechnology Conference(MNC2012), 2P-11-92, October 30-Nobember 2 (2012), Kobe, Japan

89

23. Ryo Takahashi, Takao Fukuoka, Yuichi Utsumi, “Optofluidic Device with SERS Active Three
Dimensional Gold Nanostructure”, 25th International Microprocesses and Nanotechnology
Conference (MNC2012), 2P-11-102, October 30-Nobember 2 (2012), Kobe, Japan

24. Tetsuo Harada, Masato Nakasuji, Takeo Watanabe, Hiroo Kinoshita, Yutaka Nagata,“Development of Standalone Coherent EUV Scatterometry Microscope for EUV Mask
Observation”, EIPBN2012, Hilton Waikoloa Village, Hawaii, USA, 2012/05/30.

25. Mitsunori Toyoda, Kenji Yamasoe, Tadashi Hatano, Mihiro Yanagihara, Akifumi Tokimasa,
Tetsuo Harada, Takeo Watanabe, and Hiroo Kinoshita, “At-Wavelength EUV Lithography
Mask Observation Using a High-Magnification Objective with Three Multilayer Mirrors,”
EIPBN2012, Hilton Waikoloa Village, Hawaii, USA, 2012/05/30.

26. Takeo Watanabe, Yukiko Kikuchi, Toshiya Takahashi, Kazuhiro Katayama, Isamu Takagi,
Norihiko Sugie, Hiroyuki Tanaka, Eishi Shiobara, Soichi Inoue Testuo Harada, and Hiroo
Kinoshita, “Development of the Novel Evaluation Tool with an In-situ Ellipsometer for theThickness Measurement of the Contamination Originated by the High Power EUV Irradiation
on EUV Resist”, 2012 International Workshop on EUV Lithography, Maui, Hawaii, USA,
2012/6/6.

27. Takeo Watanabe, Daiju Shiono, Yuichi Haruyama, Tetsuo Harada, and Hiroo Kinoshita,“Chemical Reaction Analysis based on the SR Absorption Spectroscopy for the High Sensitive
EUV Resist”, 2012 International Workshop on EUV Lithography, Maui, Hawaii, USA,
2012/6/6.

28. Hiroo Kinoshita, “Possibility of EUVL system at the Wavelength of 6.8 nm”, 2012 International
Workshop on EUV Lithography, Maui, Hawaii, USA, 2012/6/6.

29. Hiroo Kinoshita, Tetsuo Harada, Yutaka Nagata, Mitsunori Toyoda, and Takeo Watanabe,“Development of Actinic Mask Inspection Systems”, 2012 International Workshop on EUV
Lithography, Maui, Hawaii, USA, 2012/6/6.

30. K. Tsubakimoto, H. Yoshida, H. Fujita, N. Miyanaga, Y. Nagata, H. Kinoshita, “240W, 10kHz
Green Laser from Harmonic Converted Nd:YAG MOPA”, Advanced Lasers and Photon
Sources 2012, Yokohama, Japan, Apr. 25-27, 2012.

9031. Tetsuo Harada,

Masato Nakasuji, Takeo Watanabe, Yutaka Nagata, Hiroo Kinoshita,“Development of Coherent EUV Scatterometry Microscope with High Harmonic Generation
EUV Source”, 2012 International Symposium on Extreme Ultraviolet Lithography, Brussel,
Belgium, Sept. 30 – Oct. 4, 2012.

32. Takeo Watanabe, Daiju Shiono, Yuuichi Haruyama, Kazuya Emura, Takuro Urayama, Katsumi
Ohmori, Kazufumi Sato, Tetsuya Harada, and Hiroo Kinoshita, “The Mitigation of EUV Resist
for the High Sensitivity and the Effect of Acid Diffusion for LWR on the basis of the Chemical
Reaction Analysis”, 2012 International Symposium on Extreme Ultraviolet Lithography,
Brussel, Belgium, Sept. 30 – Oct. 4, 2012.

33. Yukiko Kikuchi, Toshiya Takahashi, Norihiko Sugie, Takeo Watanabe, Tetsuo Harada, Hiroo
Kinoshita, Kazuhiro Katyama, Isamu Takagi, Eishi Shiobara, Hiroyuki Tanaka, and Soichi
Inoue, “The Characterization of the Witness Sample Testing for the Outgassing Qualification of
EUV Resists”, 2012 International Symposium on Extreme Ultraviolet Lithography, Brussel,
Belgium, Sept. 30 – Oct. 4, 2012.

34. Isamu Takagi, Toshiya Takahashi, Norihiko Sugie, Takeo Watanabe, Tetsuo Harada, Hiroo
Kinoshita, Kazuhiro Katayama, Yukiko Kikuchi, Eishi Shiobara, Hiroyuki Tanaka, and Soichi
Inoue, “Study of Contamination due to EUV Resist Outgassing”, 2012 International
Symposium on Extreme Ultraviolet Lithography, Brussel, Belgium, Sept. 30 – Oct. 4, 2012.

35. Hiroo Kinoshita, Takeo Watanabe, Tetsuo Harada, “Recent Activities on EUVL in
NewSUBARU,” Micro Nano Conference, Kobe, Japan, Nov. 1, 2012.

36. Tetsuo Harada, Masato Nakasuji, Yutaka Nagata, Takeo Watanabe, and Hiroo Kinoshita,“Phase Imaging of EUV Mask using Coherent EUV Scatterometry Microscope,” Micro Nano
Conference, Kobe, Japan, Nov. 1, 2012.

37. Takeo Watanabe, Daiju Shiono, Yuichi Haruyama, Kazuya Emura, Takuro Urayama, Katsumi
Ohmori, Kazufumi Sato, Tetsuo Harada, and Hiroo Kinoshita, “The Analytical Mitigation of
EUV Resist for the High Sensitivity and the Low LWR using SR Absorption Spectroscopy,”
Micro Nano Conference, Kobe, Japan, Nov. 1, 2012.
38. Mitsunori Toyoda, Kenji Yamasoe, Tadashi Hatano, Mihiro Yanagihara, Akifumi Tokimasa,
Tetsuo Harada, Hiroo Kinoshita, Tsuyoshi Amano, and Tsuneo Terasawa, “An EUV

91

mask-imaging microscope for lithography generations with sub-16 nm half pitch,” Micro Nano
Conference, Kobe, Japan, Nov. 1, 2012.

39. Y. Kang, R. Takahashi, T. Fukuoka, Y. Utsumi, M. Okada, Y. Haruyama, S. Matsui, “Goldnanoparticles self-assembly assisted with imprinted HSQ pattern for SERS measurement”, 25th
International Microprocesses and Nanotechnology Conference (MNC2012), 2P-11-78, October
30-Nobember 2 (2012), Kobe, Japan

40. Hiroki Nose, Masaki Ishizawa, Takeshi Kunisada, Kazuhisa Kuroda, Akinobu Yamaguchi,
Yuichi Utsumi, “Blood separation lab-on-a-CD with controlled surface” , 7th International
Conference on Molecular Electronics and Bioelectronics (M&BE7), pp89, March 17-19 (2013),
Fukuoka, Japan

41. Yuji Yoritama, S. Yamamoto, T. Uchiyama , Akinobu Yamaguchi, Yuichi Utsumi,“Three-Dimensional Magneto Impedance Sensor using a Multi Layers Electroplating
technique” , 7th International Conference on Molecular Electronics and Bioelectronics(M&BE7), pp178, March 17-19 (2013), Fukuoka, Japan

42. Mitsuyoshi Kishihara, M. Yamashima, Yuichi Utsumi, “A Chip-Size Structure for Continuous
Microwave Irradiation by Post-Wall Waveguide”, Proc. of 2012 Asia-Pacific Microwave
Conference, 2D3-01, pp.265-267, December 4-7 (2012), Kaohsiung, Taiwan

43. Ryo Imai, Kazuhiro Fukuda, Masaharu Uemura, Takayuki Hasegawa, Muneyuki Motoyama,
Mititaka Terasawa, Kazuhiro Kanda, “The Classification of Diamond-Like Carbon Thin
Films Using BL05 in NewSUBARU”, Royal Society of Chemistry-Tokyo International
Conference 2012 (RSC-TIC 2012), Chiba, 2012/9/6-7

44. M.Uemura, T.Hasegawa, M.Sawa, N.Yokoi, N.Fukada, M.Shimizu, T.Tsurui, K.Amemiya,
T.Ohta, M.Motoyama, K.Kanda, S.Fukushima, “L-edge for the 1st period transition
elements”, The 14th European Conference on X-Ray Spectrometry (EXES 2012), Vienna,
2012/6/18-22

45. T.Hasegawa, M.Uemura, T. Tanigawa, M.Sawa, N.Yokoi, N.Fukada, M.Shimizu, T.Tsurui,
K.Amemiya, T.Ohta, M.Motoyama, K.Kanda, S.Fukushima, “K and L-edge Spectra of
Several Sulfur Compounds”, The 14th European Conference on X-Ray Spectrometry(EXES 2012), Vienna, 2012/6/18-22

9246. K. Kanda, T. Hasegawa, M. Uemura, M. Niibe, Y. Haruyama, M. Motoyama, K. Amemiya,
S. Fukushima, and T. Ohta, “Construction of a Wide-range High-resolution Beamline BL05
in NewSUBARU for Soft X-ray Spectroscopic Analysis on Industrial Materials”, The 11th
International Conference on Synchrotron Radiation Instrumentation (SRI 2012), Lyon,
2012/7/9-13

47. Y. Nakano, K. Nakamura, M. Niibe, R. Kawakami, N. Ito, T. Kotaka, K. Tominaga, ”Effectof UV Irradiation on Ar-Plasma Etching Characteristics of GaN”, 5th International
Symposium on Advanced Plasma Science and its Applications for Nitrides andNanomaterials, January 28-February1 (2013), Nagoya, Japan.

48. Y Nakano, M. Niibe, M. Lozac’h, L. Sang, M. Sumiya, ”Deep level investigation of thick
InGaN films”, 5th International Symposium on Advanced Plasma Science and its
Applications for Nitrides and , Nanomaterials, January 28-February1 (2013), Nagoya, Japan.

49. S. Honda, Y. Nosho, A. Tsukagoshi, H. Okada, M. Niibe, M. Terasawa, R. Hirase, H. Yoshioka,
H. Izumi, K. Niwase, E. Taguchi, K.-Y. Lee and M. Oura, ”Change of Diameters ofMulti-walled Carbon Nanotubes by Multiply Charged Ar Ion Irradiation”, 25th International
Conf. on Atomic Collisions in Solids, Oct. 21-25 (2012), Kyoto, Japan.

50. S. Honda, Y. Nosho, A. Tsukagoshi, S. Miyamoto, M. Niibe, M. Terasawa, T. Tokushima, Y.
Horikawa, R. Hirase, H. Yoshioka, H. Izumi, K. Niwase, E. Taguchi, K.-Y. Lee and M. Oura:
51. ”Analysis of the C1s X-ray Photoelectron Spectrum and C Kα X-ray Emission Spectrum ofMulti-walled Carbon Nanotubes Irradiated by Multiply Charged Ar Ion”, 25th International
Conf. on Atomic Collisions in Solids, Oct. 21-25 (2012), Kyoto, Japan.

52. R. Kawakami, M. Niibe, H. Takeuchi, M. Konishi, Y. Mori, T. Shirahama, T. Yamada K.
Tominaga, ”SiC Surface Damage Originating from Synergy Effect of Ar Plasma Ion andPlasma-Induced Ultraviolet Light Irradiations” 25th International Conf. on Atomic Collisions in
Solids, Oct. 21-25 (2012), Kyoto, Japan.

53. A. Tsukagoshi, R. Osugi, H. Okada, S. Honda, M. Niibe, M. Terasawa, R. Hirase, H. Yoshioka,
H. Izumi, K. Niwase, E. Taguchi, K.-Y. Lee and M. Oura, ”Spectroscopic Characterization of
Ion-irradiated Multi-layer Graphenes”, 25th International Conf. on Atomic Collisions in Solids,

93

Oct. 21-25 (2012), Kyoto, Japan.

54. S. Honda, Y. Nosho, A. Tsukagoshi, R. Mukouda, M. Niibe, M. Terasawa, R. Hirase, H.
Yoshioka, H. Izumi, K. Niwase, E. Taguchi, K.-Y. Lee and M. Oura: ”Raman and X-ray
Absorption Spectroscopic Study on Defects in Vartically Aligned Multi-walled Carbon
Nanotubes irradiated with Ar Ions”, 25th International Conf. on Atomic Collisions in Solids,
Oct. 21-25 (2012), Kyoto, Japan.

55. M. Niibe, T. Kotaka, K. Sano, R. Kawakami, K. Tominaga, Y. Nakano, ”Etching Damage
Analysis of TiO2 Thin Film with Soft X-ray Absorption Spectroscpy”, 25th International Conf.
on Atomic Collisions in Solids, Oct. 21-25 (2012), Kyoto, Japan.

56. Y. Nakano, K. Nakamura, M. Niibe, R. Kawakami, N. Ito, T. Kotaka, K. Tominaga, ”Effect of
UV irradiation on Ar-plasma etching of GaN”, International Workshop on Nitride
Semiconductors 2012, October 14-19 (2012), Sapporo, Japan.

57. S.Honda, Y.Nosho, A.Tsukagoshi, S.Miyamoto, M.Niibe, M.Terasawa, T.Tokushima,
Y.Horikawa, R.Hirase, H.Yoshioka, H.Izumi, K.Niwase, E.Taguchi, K,-Y.Lee, and M.Oura,“Electronic Structure of Multi-walled Carbon Nanotubes Irradiated by Multiply Charged Ar
Ions”, 12th International Conference on Electronic Spectroscopy and Structure (ICESS 2012),
Sait-Malo, France, September 16-21, 2012.

58. M. Niibe, T. Kotaka, T. Mitamura, ”Investigation of analyzing depth of N-K absorption spectra
measured by TEY and TFY metthods., 11th Int’l. Conf. on Syncrotron Rad. Instrum., 9-13 July(2012), Lyon, France.

59. M. Niibe, K. Koida, Y. Kakutani, ”Contamination Experiment for Mo/Si Multilayer Mirrors
with the use of Single-bunch Synchrotron Radiation”, 11th Int’l. Conf. on Syncrotron Rad.
Instrum., 9-13 July (2012), Lyon, France.

60. Y. Kang, Y. Nakai, M. Okada, Y. Haruyama and S. Matsui, “Characteristics of mechanicalvibration in imprinted nanostructures”, The 56th International Conference on electron, ion,
photon beam technology and fabrication, Hawaii, 2012/5/30

61. M. Okada, M. Kurita, E. Nishioka, M. Kondo, Y. Haruyama, A. Emoto, H. Ono, N. Kawatsuki
and S. Matsui, “Pattern-size Effect of Reorientation of Photoinduced Liquid Crystalline

94

Polymer by Thermal Nanoimprinting”, The 56th International Conference on electron, ion,
photon beam technology and fabrication, Hawaii, 2012/5/30

62. M. Okada, M. Kurita, E. Nishioka, M. Kondo, Y. Haruyama, A. Emoto, H. Ono, N. Kawatsuki
and S. Matsui, “Reorientation Evaluation of Bidirectional Line Pattern on Photoinduced Liquid
Crystalline Polymer Fabricated by Thermal Nanoimprinting”, The 56th International
Conference on electron, ion, photon beam technology and fabrication, Hawaii, 2012/5/30

63. S. Iyoshi, M. Okada, Y. Haruyama, S. Matsui, K. Kobayashi, S. Kaneko, M. Nakagawa, H.
Hiroshima, “Study of demolding Characteristics in continuous UV nanoimprinting”, The 56th
International Conference on electron, ion, photon beam technology and fabrication, Hawaii,
2012/5/30

64. K. Kanda, T. Hasegawa, M. Uemura, M. Niibe, Y. Haruyama, K. Amemiya, S. Fukushima, T.
Ohta, “Construction of a Wide-range High-resolution Beamline BL05 in NewSUBARU forSoft X-ray Spectroscopic Analysis on Industrial Materials”, The 11th International Conference
on Synchrotron Radiation Instrumentation, Lyon, France, 2012/7/12

65. Y. Haruyama, M. Okada, T. Ishida, S. Matsui, “Evaluation of the fluorinated self-assemblemonolayer by using photoemission and absorption spectroscopy”, Asian Conference on
Nanoscience & Nanotechnology 2012, Lijiang, China, 2012/9/7

66. Y. Haruyama, M. Okada, and S. Matsui, “The electronic structure of the fluorinatedself-assemble monolayer by photoemission and absorption spectroscopy”, The 12th
International Conference on Electron Spectroscopy and Structure, Saint-Malo, France,
2012/9/17

67. M. Okada, E. Nishioka, M. Kondo, Y. Haruyama, T, Sasaki, H. Ono, N. Kawatsuki and S.
Matsui, “Reorientation Pattern Of Photoinduced Liquid Crystalline Polymer Imprinted By
Thermal Nanoimprinting Using A Dot Pattern Mold”, The 38th International Micro & Nano
Engineering Conference, Toulouse, France, 2012/9/17

68. Y. Kang, M. Okada, Y. Haruyama and S. Matsui, “Residual Layer Removal By Reactive Ion
Etching”, The 38th International Micro & Nano Engineering Conference, Toulouse, France,
2012/9/17

9569. M. Okada, Y. Haruyama, and S. Matsui, “Frictional Force Measurement By Scanning Probe
Microscopy Using Cantilever With And Without Antisticking Layer”, The 38th International
Micro & Nano Engineering Conference, Toulouse, France, 2012/9/17

70. M. Okada, E. Nishioka, M. Kondo, Y. Haruyama, T, Sasaki, H. Ono, N. Kawatsuki and S.
Matsui, “Reorientation of Photoinduced Liquid Crystalline Polymer Induced by Thermal
Nanoimprinting with Linearly Polarized UV Irradiation”, The 11th International Conference on
Nanoimprint & Nanoprint Technology, Napa, USA, 2012/10/25

71. M. Okada, Y. Haruyama, and S. Matsui, “Evaluation of interaction between antisticking layerand UV nanoimprint resin by scanning probe microscopy”, The 11th International Conference
on Nanoimprint & Nanoprint Technology, Napa, USA, 2012/10/25

72. Y. Kang, R. Takahashi, T. Fukuoka, Y. Utsumi, M. Okada, Y. Haruyama, and S. Matsui,“Self-assembly of gold particles using imprinted HSQ pattern for SERS measurement”, The
11th International Conference on Nanoimprint & Nanoprint Technology, Napa, USA,
2012/10/26

73. S. Iyoshi, M. Okada, K. Kobayashi, S. Kaneko, T. Katase, K. Tone, Y. Haruyama, M. Nakagawa,
H. Hiroshima and S. Matsui, “ Study of the Resistance of Antisticking Layer on Repeated UVNanoimprint”, 25th International Microprocesses and Nanotechnology Conference, Kobe,
2012/11/1

74. T. Watanabe, D. Shiono, Y. Haruyama, K. Emura, T. Urayama, K. Ohmori, K. Sato, T. Haradaand H.Kinoshita, “The Analytical Mitigation of EUV Resist for the High Sensitivity and the
Low LWR using SR Absorption Spectroscopy”, 25th International Microprocesses andNanotechnology Conference, Kobe, 2012/11/1

75. M. Okada, E. Nishioka, M. Kondo, Y. Haruyama, T. Sasaki, H. Ono, N. Kawatsuki and S.
Matsui, ”Optical Evaluation of Photoinduced Liquid Crystalline Polymer Pattern fabricated by
Thermal Nanoimprinting with Linearly Polarized UV Irradiation”, 25th International
Microprocesses and Nanotechnology Conference, Kobe, 2012/11/1

76. Y. Sawada, H. Miyake, T. Ohsaki, M. Okada, S. Iyoshi, Y. Haruyama, H. Hiroshima and S.
Matsui, “Thickness Dependency of Polymerization Efficiency on UV-nanoimprint Resins”,
25th International Microprocesses and Nanotechnology Conference, Kobe, 2012/11/1

96

77. Y. Kang, R. Takahashi, T. Fukuoka, Y. Utsumi, M. Okada, Y. Haruyama and S. Matsui, “Gold
Nanoparticles Self-assembly assisted with Imprinted HSQ Pattern for SERS Measurement”,
25th International Microprocesses and Nanotechnology Conference, Kobe, 2012/11/2

78. M. Chinen, Y. Kang, M. Okada, Y. Haruyama, H. Hiroshima and S. Matsui, “Evaluation ofInteraction Force between UV Resin and F-SAMs by Dynamic Contact Angle Measurement in
PFP Gas Ambient”, 25th International Microprocesses and Nanotechnology Conference, Kobe,
2012/11/2

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98

Academic Degrees

Academic Degree

DegreeName

Master’s Thesis

Master of
Science

Daisuke Tonaka

Development and evaluation of energy band expansion of laser Compton
scattering gamma-ray source

Master of
Science

Yousuke Hamada

Master of
ScienceYasuhisa KITAGAWA(University of Hyogo)

Study on Evaluation of Laser Compton Scattering Gamma-ray Source

Master of
Science

Sayaka CHIN
(University of Hyogo)

Development of THz radiation Source by Compact LINAC LEENA(University of Hyogo)(University of Hyogo)

Stabilization of electron storage ring by auto adjustment of betatron tune

Master Of Takuya KOTAKA
Engineering (University of Hyogo)

Development of spectroscopic methods using soft X-ray emissions inBL9a at the NewSUBARU SR facility

Master of
Luo WULIN
Engineering (University of Hyogo)

Fabrication of flexible light guide plate using hot-embossment

Master of
Zhu XIAOZIEngineering (University of Hyogo)Hot-embossing fabrication of diffraction grating with narrow line width

Master of
Yuu KUBOYAMAEngineering (University of Hyogo)

Evaluation of compact capacitance type inclination sensor fabricated by
LIGA process

Master of
Yuji YORITAMA
Engineering (University of Hyogo)

Study on microfabrication process for magnetic and optical devices

Master of
Hiroki NOSEEngineering (University of Hyogo)

Study on full protocol control using three-dimensional Lab-on-a-CD

Master of
Masato NAKASUJI
Engineering (University of Hyogo)

Development of the coherent EUV scatterometry microscope with thehigh-order-harmonic generation EUV source

Master of
Takuro URAYAMAEngineering (University of Hyogo)

Development of the EUV interference lithography system for theevaluation of 1x-nm-node EUV resist

Master of
Akifumi TOKIMASA
Engineering (University of Hyogo)

Development of the EUV microscope using a high-magnification
objective for the EUV mask evaluation

Master of
Science

Mika CHINEN(University of Hyogo)

Study of release property of UV resin and antisticking layer in PFP gas
ambient by contact angle measurement

Master of
ScienceYohei SAWADA(University of Hyogo)

Study of curing process of UV nanoimprint resin

DegreeName

Docter’s Thesis

Docter of
Tomoaki INOUE
Engineering (University of Hyogo)

Study on intense soft X-ray generator using laser-produced plasma

99

100

Cover photographs
15MeV Compact Electron Linear Accelerator LEENA

Using relativistic electron beams of a compact electron linear accelerator LEENA, the development ofterahertz radiation sources is in progress at our laboratory.
Electron beams from a RF gun with a thermal cathode are bunched at an alpha magnet and accelerated by a 15
MeV standing wave linac.
Smith-Purcell light in terahertz regime is emitted from a surface of metal, when an electron passes through theneighborhood of the metal grating.
The light was taken out from a vacuum chamber by three movable mirrors into the atmosphere.
The wavenumber spectrum of the light is measured with Martin-Puplett interferometer, in which wire gridpolarizer is used to split terahertz light.

"Smith-Purcell grating and"Martin-Puplett interferometer."mirrors in the vacuum chamber."

101

LASTI Annual Report 2012 Vol.14(2012)2013.10 Published byLaboratory of Advanced Science and Technology for Industry, University of Hyogo
3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1205 JAPANTEL: +81-791-58-0249 / FAX: +81-791-58-0242

Editorial board

Editor in Chief
Editors

102

Shinji Matsui
Kazuhiro Kanda
Yoshihiko Shoji
Masahito Niibe
Yuichi Utsumi
Takeo Watanabe