PREFACE
This annual report reviews the research activities of the Laboratory of Advanced
Science and Technology for Industry (LASTI) in the academic year of 2017 which is from
April 2017 to March 2018) including research activities using NewSUBARU light sourceat the SPring-8 site and other research activities of the micro and nanoscale are carriedout energetically at the Center for Advanced Science and Technology (CAST) II.
NewSUBARU facility has a 1.0-1.5 GeV electron storage ring, which provides lightbeams from IR to Soft X-ray regions. The researches which are carried out are the lightsources for next generation through a machine R and D, and the industrial applications
such as EUVL lithography, LIGA process, material analysis.
The annual report describes mainly that topics of the NewSUBARU research
activities of this year including 1) the research and development of gamma ray
application at BL1 beamline, 2) the next generation lithography by Extreme UltraViolet(EUV) lithography at BL3, BL9B, BL9C, and BL10 beamlines, 3) Lithographie,
Galvanoformung, and Abformung (LIGA) process technology at BL2 and BL11
beamlines, 4) the chemical analysis using soft X-ray absorption fine structure at (BL5,
BL9A, and BL7 beamlines and soft X-ray emission spectroscopy at BL5 and BL9A
beamlines at soft X-ray energy region.
Most of our research activities are being conducted in collaboration research works
with industries, research institutes, and other universities, inside and outside Japan.
We will continue to respond to the community’s demand by offering new science andtechnology.

Takeo Watanabe

Director of Laboratory of
Advanced Science andTechnology for Industry,
University of Hyogoi

ii

Staff of NewSUBARU（（In front of Advanced Research Building）

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 Application for Advanced Technology

Advanced Photon System
Beam Physics
Nanostructure Science and Technology
Guest Chair

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

Staff (FY 2017)
Research and faculty staff
WATANABE Takeo, Professor , Director
MIYAMOTO Shuji, Professor
KANDA Kazuhiro, Professor
UTSUMI Yuichi, Professor
SUZUKI Satoru, Professor
NIIBE Masahito, Associate Professor
SHOJI Yoshihiko, Associate Professor
HARUYAMA Yuichi, Associate Professor
YAMAGUCHI Akinobu, Associate Professor
AMANO Sho, Research Associate
HASHIMOTO Satoshi, Research Associate
HARADA Tetsuo, Research Associate
OKADA Makoto, Research Associate

Administrative staff
HAYASHI Masahiko, General Manager
ISHIHARA Yasunori, Manager
KURODA Takashi, Chief
KANATANI Naoko, NewSUBARUKUWATA Ayami, NewSUBARU
YAMAMOTO Keiko, CASTYOKOYAMA Yuka, CAST
HASEGAWA Miwa, CASTAKAMATSU Sumiyo, CAST
FUJIMAKI Hisae, CASTYAMAMOTO Mako, CAST
KUSUMOTO Kumi, CAST
Coordinator
FUKADA Noboru, NewSUBARUFUKUOKA Takao,CAST

Specially appointed staff
KINOSHITA Hiroo, Professor
TERANISHI Nobukazu,Professor

Guest staff
MOCHIZUKI Takayasu, Professor
MATSUI Shinji, Professor
OHKUMA Haruo, Professor
ASANO Yoshihiro, Professor
FUKUSHIMA Sei, Professor
BAN Hiroshi,Professor
KUDOU Hiroto, Professor
HORIBE Hideo,Professor
NAGATA Yutaka, Assistant Professor
HARADA Yoshihisa, Assistant Professor

Contact address

Advanced Research Building
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
Accesshttp://www.lasti.u-hyogo.ac.jp/NS-en/access/

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Part 1. Current Status of NewSUBARU
and Other Light Source

Staff of NewSUBARU（In front of NewSUBARU Facility）

NewSUBARU Storage Ring
Shuji Miyamoto, Satoshi Hashimoto, Yoshihiko Shoji,
Yasuyuki Minagawa, Kazuyuki Kajimoto, Yusuke Hamada
LASTI, University of Hyogo

1. Storage Ring Parameters
The machine parameters of the NewSUBARU
storage ring are listed in Table I. The machinecondition remains the same with last year.

Machine tuning(12.1 %)
Machine study(6.9 %)

Table I Main parameters of the NewSUBARU
storage ring.
Circumference
118.73 m
Lattice
DBA+Inv. bending
Number of bending
12
Radius of curvature
3.217m
RF frequency
499.955 MHz
Betatron tunes
H: 6.30, V:2.23
Bunch length (sigma) 33ps (normal operation)
Harmonic number
198
Radiation loss per turn 33.4 keV (@1GeV)Electron energy
1.0GeV
1.5GeV
Mode
TopUp
Decay
Natural energy spread 0.047%
0.072%Natural emittance
50 nm
112 nmStorage current
300 mA
350mA

Beam downtime (1.1%)

User time(81.0%)

Total operation
2460h(100 %)Fig.1 Operating time breakdown of
NewSUBARU storage ring in FY2017.
time of the electron storage ring. 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 down time due to themachine trouble was 1.1 % of the total operation
time.
Figure 2 shows overview of the NewSUBARU
electron storage ring. The ring is consisted with 6
DBA cells with an inverse bending magnet with
auxiliary coil. There are 6 straight sections between
each cells, and they are used for an injection
septum, an accelerating RF cavity, two undulators
and a laser Compton scattering gamma ray source.
Electrons are injected from the linac of SPring-8
through the beam transport line (L4BT).

2. Operation Status
The ring has two user-time operation modes, 1.0
GeV top-up operation mode and 1.5 GeV current
decay operation mode. The basic operation time is
9:00 - 21:00 of weekdays. Monday is used formachine R&D, Tuesday is for 1.5 GeV user time,
Wednesday and Thursday are for 1.0 GeV top-up
user time, Friday is for 1.0 GeV or 1.5 GeV user
time. Night period or weekend is used for machine
study and user time with the special mode, such asa single bunch operation and a changing theelectron energy, if necessary. Range of the electronenergy is from 0.5 GeV up to 1.48 GeV with 1
MeV step.
The total machine time in FY2017 was 2460 hrs,
99.5% of that of FY2016, excluding the beam downtime. Figure 1 shows the breakdown of operation

3. Machine Trouble
The machine troubles in FY2017 are listed inTable II. The typical hardware troubles were as
follows.
(1) Instability of the new switching power supply
for auxiliary coil of the inverse bending magnet.
This type of power supply occasionallyoscillates at low operation current. The trouble
was settled by changing the deceleration

Table II Machine troubles in FY2017.
Group

Failure / trouble

down time (hr)Safty interlock
ControlBeam line, L4BT monitor, Emergency earthquake
GUI, VME, Operator console, Signals

0.00
10.77

MagnetOther
Total

Power supply failure, interlock
Vacuum, Instability, UPS

1.58
13.63
25.98

1

L4BT

OTR
monitorInjection

NewSUBARU storage ring
RF cavity

Bump magnets

Short
undulator

Long undulator
Auxiliary coils
on inv. bending magnets
Laser Compton scattering γ-ray

Fig.2. Layout of NewSUBARU electron beam transport line (L4BT) and storage ring. The electron
beams are injected from the linac at SPring-8 to the storage ring through transport line.

sequence to keep a sufficient current in auxiliary
coil even at low energy operation.
(2) Interlock alarm of power supply.
Power supply for quadruple magnet families
often showed “Heat” alarm at start up time. The
automatic startup sequence stopped due to thisalarm. We are planning to update the quadruple
power supply.

Realtime image analysis system for beam profile
monitor was developed. This was used for fivemonitors in the L4BT transport line. The
quantitative beam profile and trajectory data
improves improved stability of every day injection
tuning.
In addition, new OTR beam profile monitor was
installed at beam transport line (L4BT). This
improved quality of profile monitoring of electron
beam compared with the fluorescent plate monitor.
Automatic betatron tune control system is being
developed at NewSUBARU. High performancereal-time spectra analyzer system (Tektronix
RSA306B) realized stable tune monitoring.
The computer aided accelerator control system isbeing continually improved, for the automaticelectron beam injection, acceleration anddeceleration.

(3) Failure of bump magnet power supply.
One of the fore bump magnet was failed dueto the broken of the control power supply. This
was temporary repaired. All four power supplies
will be updated.
(4) Vacuum leak at beam line absorber.
Gradual deterioration of vacuum was detected
at a one of the beam line absorber section. The
beam line absorber was temporary exchanged
with a rigid absorber. This beam line could not
be used for about three months, now permanent
repair is completed and it is ordinary use.

5. Summary
The NewSUBARU synchrotron light facility has
been 20 years since construction. Failures of various
equipment are increasing. We will intend to continue
stable and sophisticated operation with appropriate
inspection and necessary updates of equipments.

4. Machine Study and Special User Time
Table III shows the list of machine studies in FY
2017. Some improvements on the operation ofaccelerator were performed.

Table III List of machine studies and special user mode in FY2016.
(unit is an operation shift = 12 hrs)
R & D theme and special user mode
New filling test for TOF
Accelerator tuning
Deceleration sequenceLong undulator tuning
Mirror & Beamline burnt out by SR
Deceleration sequence
Educational student experiments

Responsible person
S.Miyamoto
S.Hashimoto, Y.Shoji
S.Miyamoto
S.Hashimoto
K.Kanda, M.Niibe, Y.Haruyama
S.Miyamoto
Y.Haruyama

2

Operation shifts
3
5
5
2
5
5
3

Beamlines
Masahito Niibe
LASTI, University of Hyogo
The arrangement of the beamlines in the
NewSUBARU synchrotron radiation (SR) facility isshown in Fig.1. Total nine beamlines are operating in
the NewSUBARU SR facility.
Four beamlines of BL01, 03, 06 and 11 wereconstructed until 1999. Three beamlines of BL07, 09
and 10 were started the operation from 2000.
BL02 beamline was constructed for the usage of
LIGA in 2003.
BL03B beamline branched from the BL03
beamline propose for the usage of the EUVL

(extreme ultraviolet lithography) microscope for the
EUVL finished mask inspection.
BL05 beamline was constructed in response to ademand in the industrial world in 2008, which is theenhancement of the analysis ability in the soft X-ray
region with the development of nanotechnology.
BL09B beamline branched from BL09 beamline
for 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 originatedto the resist outgassing during the EUV exposure.

Fig. 1 Beamline arrangement in NewSUBARU.

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I. BL01
BL01 is a beamline for research and developing
new light sources.
Present light source is apolarized quasi-monochromatic gamma-ray beam
generated by the laser Compton scattering. Photon
energy range of this gamma-ray beam source is from
1MeV to 76MeV with a maximum power of
0.33mW. The layout of the beamline BL01A isshown in Fig.1. This beamline consists of a longstraight section on NewSUBARU storage ring and
two gamma-ray irradiation hutches.� Laser beams
are injected from the downstream side of thebeamline, and the scattered gamma rays concentrate
at narrow divergence angles in the electron beam
traveling direction and propagates through theatmosphere, passes through the lead collimator, andreach to the irradiation hatches.
Specification of this gamma-ray sources are listed
in Table 1. Gamma-ray irradiation hutch just outsideof the storage ring tunnel was constructed in 2004
for gamma-ray experiments. Second gamma-ray
irradiation hutch "GACKO" was installed forcollaborating with Konan University in 2012. Table
2 shows the measured gamma-ray flux at “GACKO”.
Table 1. Specification of BL01 gamma beam
Max gamma-ray beam power
0.33 mW
Gamma-ray energy range
1.0 - 76 MeV
Gamma-ray polarization>95%*
Gamma-ray beam divergence
0.5 mrad***with 3mmφ collimator.
** Ee=1.0 GeV.
(measured at the irradiation hutch "GACKO")

Fig.1 Layout of the gamma-ray beamline BL01.
Table 2. Measured gamma-ray photon energy and flux at GACKO
Laser
Ee=982 MeV, Ie=300mA
Ee=1480 MeV, Ie=300mA
CO2 laser
Eγ=1.73 MeV
Eγ=3.92 MeV
λ=10.52 µm, P=10W Fγ=6 x105 γ/s (ΔE=10%)
Fγ=6 x105 γ/s (ΔE=20%)
Nd: YVO4 laser
EγEγ
λ=1.064 µm, P=10W 17.0 MeV: Fγ=7 x105 γ/s (ΔE=5%)
38.1 MeV, Fγ=7 x105 γ/s (ΔE=8%)5
λ=0.532 µm, P=10W 33.3 MeV: Fγ=3 x10 γ/s (ΔE=5%)
74.3 MeV, Fγ=3 x105 γ/s (ΔE=10%)*with 3mmφ collimator
Ee is electron energy, Ie is electron current, Eγ is gamma-photon energy and Fγ is gamma-photon flux.
II. BL02
The LIGA (abbreviated name of Lithogaphic,
Galvanoformung and Abformung) process which
consists from deep X-ray lithography, electroforming,and molding process is one of the promising
candidates for such 3D micofabrication. More thanhundreds aspect ratio for microstructure can be4attained by the usage of the higher energy X-rays(4-15 keV) from synchrotron radiation (SR) withdeeper penetration depth to the photosensitive resist.
In this system we have succeeded to enlarge theexposure area up to A4 size and the fabrication
dimension from submicron to millimeter by varying
the energy of the X-ray source in accordance withthe size of desired microparts. Microstructure withhigh aspect ratio over several hundred will beachieved using the X-rays over 10 keV since highenergy X-ray has deep penetration depth to thephoto-sensitive resist materials. Whereas, in the caseof lithography for low energy X-rays from 1 keV to
2 keV, submicron structures with high aspect ratio
will be achieved using the X-rays mask with precise
line-width and thinner absorber, since low energy
X-rays has low penetration depth. Based on thisprinciple, the beamline for x-ray exposure haveconstructed with continuous selectivity of X-rays
from 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
performance of 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 the end-station (<10-9 Pa) at
which gasses for substrate cooling will be introducedin the exposure apparatus.
The flexibility for the shapes and functions of
microstructure will be enlarged by achieving 3D
microfabrication process using multi step exposure
at various configuration between X-ray mask andsubstrates. 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 loadof sample substrate suffered during SR irradiation
helium introduction and substrate coolingmechanism were also equipped. Specification ofspectrometer is listed in Table 3.

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 (EUV) lithography. The extreme
ultraviolet lithography (EUVL) is a promise
technology for fabricating a fine pattern less than
7-nm node. There are (1) a EUV resist-sensitivity
evaluation tools, (2) a VUV reflectometer, and (3) an
EUV microscope with Schwarzschild optics. At (1)tool, EUV resist is exposed with SR light of EUV
monochromatized by 7 Mo/Si multilayer mirrors.
The exposure spectrum of this tool was same as the
ASML exposure tools. The monochromator of (2)reflectometer was UV – VUV reflectometer. At EUV
Mount type
Grating
Energy range

lithography, out-of-band radiation (100 – 300 nm) of
EUV source degrades image quality. Thus, optics
and resist property of out-of-band region wasessential to evaluate, for example EUV mask
reflectivity, and EUV resist sensitivity. The
monochromator specification was shown in Table 4.
The EUV microscope (3) has Schwarzschild optics,
which were fabricated with collaboration of Dr.
Toyoda (Tohoku Univ.). The spatial resolution wasquite high of less than 28 nm, which was equal to 7
nm at wafer printing size.

Table 4. VUV monochromator specification
Collimateplane
monochromator
Plane Grating (1,000 l/mm)
4 - 120 eV (UV ～ VUV)

5

gratingResolving power (E/ΔE)～1000

IV. BL05
BL05 was constructed in response to a demandin the industrial world, which is enhancement of theanalysis ability in the soft x-ray region with thedevelopment 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 tocover the energy range of 1300-4000 eV and
50-1300 eV, respectively. The incident beam fromthe bending magnet is provided for two branch lines
through different windows of a mask. Therefore,
these two branch lines can be employedsimultaneously. At the end stations of each branch,
the transfer vessel systems were mounted for themeasurements of sample without exposure to air. In
Monochromator

addition, globe box was placed for the preparation ofsamples into transfer vessel.
1) The double crystal monochromator was
installed at the BL05A. InSb, Ge, Si, SiO2, Beryl and
KTP 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 be measured for samples at the end
station filled with He gas. Table 5 shows the
specification of monochromater.

Table 5. Monochromator specification
Double crystal monochromator
SiO2（1010）, InSb（111）, Ge（111）, Beryl（1010）, KTP（110）, Si

Monochromator crystals
Energy range
Resolution（111）
1300-4000 eV
E/⊿E=3000

2)
The
constant-deviation
monochromatorconsisting of a demagnifying spherical mirror and avaried-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°.
Monochromator
Grating
Energy range
Resolution

Two measurement chambers are prepared at the end
station of BL05B. The XAFS spectra in the total
electron yield mode and fluorescence XAFS spectrausing SDD (Ourstex) can be measured in a highvacuum chamber. In addition, the photoelectron
spectrum can be measured using spherical electron
analyzer (VG Sienta, R3000) in an ultrahigh-vacuum
chamber. The chambers can be replaced by eachother within 1 hour. Table 6 shows the specificationof 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/⊿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 3°. The SR at BL06

sample stage had a continuous spectrum from IR tosoft x-ray, which was lower than 1 keV. A differential
pumping system can be utilized for experiments in a
gas atmosphere, which is difficult in the soft x-ray
region. A sample holder can install four pieces ofsamples at a time. By using heater set in the sample

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holder, the sample can be heated from room
temperature to 220C. The temperature of sample ismonitored using a Cr-Al thermocouple mounted on
the sample holder.

VI. BL07A and BL07B
This beamline was designed for the developmentof new materials by SR technology. This beamline
consists of two branch lines, which are provided withan incident beam from a 3-m-long undulator byswitching the first mirror. One of them is a highphoton-flux beamline with a multilayered-mirror
monochromator for the study of SR-process(BL07A) and another is a high-resolution beamlinewith a varied line spacing grating monochromator
for the evaluation of nano-structure characteristics
by SR-spectroscopy (BL07B). The useful range ofemitted photons from 50 to 800 eV is covered at bothbeamlines. The light source of BL07 is a 3-m lengthplanar undulator, which consists of 29 sets ofpermanent magnets, a period length of which is 76
mm. The incident beam from the undulator isprovided for two branch lines by translationalswitching of first mirror.

The multilayered-mirror (MLM) monochromator,
which has high reflectivity in the soft X-ray region,
was installed 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, forfocusing. 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 of filter. The flux deliver by this design isestimated to be between a maximum of 1017
photons/s at 95 eV and a minimum 21014 photons/s
at 300 eV for a 500 mA ring current. Table 7 shows
the summary of BL07A. In addition, X-ray
fluorescence (XRF) apparatus using spherical variedline spacing grating was mounted at the downstreamof irradiation chamber. The poly capillary was usedtoenhancebeam-condensing
efficiency.
Measurement energy range was from 30 eV to 450
eV. This XRF apparatus was expected to utilize thechemical analysis on the light metals, Li and Be, andlight elements, B, C and N.

1) BL07A
Energy
range
(eV)
50-60

4
0
0
0

60-95
90-140140-19190-40400-56

Table 7. Summary of BL07A.
Multilayer mirror
Material
spacinThicknnumber
E/E
g
ess
of
Ratio
layers
Mo/Si
Mo/B4C
Ni/C

20 nm
11 nm
5 nm

0.8

20

0.5

25

0.5

60

550-806.2 %alFiltermateri
Al

100
nm

None



Ag

100
nm

Cr

500
nm
500
nm

3.3 %
2.5 %

Ni

2) BL07B
The
constant-deviation
monochromatorconsisting of a demagnifying spherical mirror andvaried line spacing plane grating (VLSPG), which

Thickness

can provide to high resolution, simple wavelength
scanning with fixed slits, was mounted on BL07B.
The optical system consists of a first mirror (M0), an
entrance slit (S1), a premirror (M1), and three kinds

7

resolution in extreme ultraviolet region bydiminishing various kinds of aberration. The total
resolving power about 3000 can be realized in thewhole energy region. Table 8 shows the specificationof the monochromator.

of plane grating (G), an exit slit (S2) and two
focusing mirrors (M2 and M3). The monochromator
is designed to cover the energy range 50-800 eV withthree gratings, of which including angle are 168.
The VLSPG has been well known to obtain highTable 8. Monochromator specification
Mount type
Hettrick-Underwood type
Grating G1, G2, G3
Plane VLS (600, 1200, 2400 l/mm)
Energy range
50-150 eV, 150 – 300 eV, 300-800 eVResolving power (E/ΔE)～3000

VII. BL09
A purpose of this beamline is studies on a soft
x-ray interferometry or a holographic exposure
experiment with making use of highly brilliant andcoherent photon beams radiated from 11 m longundulator in NewSUBARU.
BL09 consists of M0 mirror, M1 mirror, G
grating and M2 mirror. M0 mirror is used forhorizontal deflection and beam convergence, M1 isused for vertical beam convergence at the exit slit,
and M2 is used 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 and0.27 mrad in vertical. The acceptance can be
restricted by 4-jaw slits equipped at upstream of theM0 mirror.
BL09A beamline is used for material analysis:
X-ray absorption spectroscopy (XAS) and X-ray

photoelectron spectroscopy (XPS). In 2013, X-ray
emission spectrometer (XES) was introduced at theendstation of the BL-09A. The energy range andresolving power of the XES system was designed to
be about 50-600 eV and 1500, respectively.
BL09B beamline branched from BL09 beamline
for the usage of the EUV interference lithography forthe evaluation of the exposure characteristics of
EUV resist. Coherence length of 1 mm at the resist
exposure position was achieved using BL09B
beamline. And BL09C beamline branched from
BL09B beamline for the usage of the thickness
measurement of the carbon contamination originatedto the resist outgassing during the EUV exposure.
Table 9 shows the specification of themonochromator.

Table 9. Monochromator specification
Mount typeMonk-Gillieson type
Grating
Plane VLS (300, 900, 1200 l/mm)
Energy range
50 – 750 eVResolving power (E/ΔE)～3000
VIII. BL10
BL10 is for EUV reflectometry and soft X-ray
analysis. M0 mirror is used for horizontal deflection
and beam convergence, M1 is used for vertical beam
convergence at the exit slit, and M2 is used forvertical deflection and beam convergence. A
monochromator is constructed by M1 and a planegrating. At the beginning, the multilayer reflectivity
measurement was carried out at this beamline. The
characteristics of this beamline and the result of the

Mo/Si multilayer measurement are carried out for thedevelopment of the EUV- mask technology.
BL10 utilizes a monochromator of thevaried-line-spacing plane grating (VLS-PGM). Theline density of the monochromator in central regionof the gratings were 600, 1800 and 2,400 lines/mm.
The reflectometer has a two axis vacuum goniometer.
One axis carries the sample, which may be a mirror
surface at the center of the reflectometer vacuum-motion) carries
chamber8the detector on a rotating arm. In addition there arelinear motions to translate the sample in two
orthogonal directions (x,y). All motors are controlled
by computer. The reflectivity result obtained at BL10
has a good agreement with that at LBNL. Table 10shows the specification the monochromator.
The micro-CSM tool was adapted at the mostdownstream of the BL10 beamline for the EUV mask
defect inspection with coherent-diffraction-imaging

method. This too is very effective for the inspectionof the actinic patterned mask with phase imaging.
A large reflectometer was installed in a branch line
for large EUV optical component including EUV
collector mirrors. The reflectometer has a sample
large optical elements with a maximum weight of 50kg, a diameter of up to 800 mm, and a thickness of
250 mm. The entire sample surface is able to bemeasured.

Table 10. Monochromator specification
Mount typeMonk-Gillieson type
Grating
Plane VLS (600, 1800, 2400 l/mm)
Energy range
50 – 1,000 eVResolving power (E/ΔE)～1000
IX. BL11
A beam line BL11 is constructed for exposure
Hard X-ray Lithography (DXL) in the LIGA
(Germanacronymfor
Lithographite
Galvanoformung and Abformung) process. LIGA
process, that utilizes a useful industrial applicationof SR, is one of the promising technologies forfabrication of extremely tall three-dimensional (3D)
microstructures with a large aspect ratio. This
process was invented at the Institut Fur
Mikrostrukturtechnik (IMT) of the Karlstuhe
Nuclear Center (KfK) in 1980. Microstructures withheight 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, andso on. This beam line was designed by the criteria ;photon energy range from 2 keV to 8 keV, and aconsisting of an absorber chamber, a first-mirror
chamber (M1), a 4-way slit chamber, a Be andpolyimide window chamber, and an exposure
chamber. The horizontal angle of the outgoing SR
could be obtained up to 17.8 mrad, providing abeam spot size on the exposure s
mm2. The micron-scale structure with high aspectratio will be achieved using the toroidal typed
mirror M1 which can produce a parallel collimatedbeam of X-rays. In addition, the homogeneity of thebeam is excellently controlled by a novel adding
system. �
Using the precision stage in the exposure
chamber, the flexibility for the shaped and functionsof microstructure will be enlarged by achieving 3D
microfabrication process using multi step exposure
at various configuration between x-ray mask andsubstrates. The exposure area of 200 mm × 200
mm is brought to fruition. In order to decrease theheat load of sample substrate suffered during SR
irradiation, helium introduction and substratecooling system were also equipped. The
specification of the LIGA exposure system is listed
in Table 11.

112

photons/cm . The BL11 can provide the mostsuitable photon energy for microfabrication in X-ray
lithography, while the BL2 is equipped for
fabricating fine pattern submicron-scale structure
and microstructure with high aspect ratio byselectivity of X-rays using movable mirror system.
That is, LIGA process in NewSUBARU can provide
the best 3D microfabrication because the BL11 andBL2 are complementary. The beamline BL11 is

Table 11. Specification of the LIGA exposure system
Exposure method
Proximity exposure
Wafer size
8 inchExposure area
200 mm(H)×200 mm(V)
Exposure environment< 1atm (He-gas)

9Analysis was launched in August 2016. As anorganization crossing in university courses, thiscenter is consulted and administered by all membersof the LASTI related to analysis, and in collaboration
with the SR Nanotechnology Center of Hyogo
Prefecture, a wide range of energy from hard X-rays
to soft X-rays. We aim to respond to various analysis
needs of the area on a one-stop basis.

Establishment of Research Center for Advanced
Synchrotron Radiation Analysis
In order to respond to diverse analysis needs fromindustries, it is necessary to advance technologicaldevelopment for analyzing beamlines (BLs) of
NewSUBARU SR facility to advance integrated andstrategic development of analyzing technology. For
this reason, the Research Center for Advanced SR
Acknowledgement
We would like to thank all the staff who work at
NewSUBARU synchrotron radiation researchfacility for their help to describe the update details of
the beamlines.

10

Recent improvements on accelerator equipment of
NewSUBARU storage ring
Satoshi HASHIMOTO1, Shuji MIYAMOTO1, Kazuyuki KAJIMOTO2, Yasuyuki MINAGAWA2
1. LASTI, University of Hyogo 2. JASRI / SES

Abstract

We have been working on improving various kinds of accelerator equipment for more stable
operation and the advancement of the NewSUBARU electron storage ring. In this paper we
introduce the recent successful improvements on beam monitor systems.

Introduction
NewSUBARU synchrotron radiation facility[1,2] has been operated for nearly 20 years. At
NewSUBARU, soft X-ray, EUV light and
gamma ray by Compton scattering have beenused for mainly industrial applications.
For the stable operation of the accelerator,
the measurement and the control of electron
beams with higher precision are key issues. In
this paper we report the recent improvements ofdevices for the NewSUBARU storage ring suchas;(1) Profile monitors
Keeping the beam injection efficiency highfor a long time is important for a top-up
operation of the ring. And it is necessary toknow always the status of injected beams. Foran easy control of devices and reliablemeasurements, we upgraded beam profile
monitor systems for measuring the status of
injected beams.
(2) OTR monitor
We newly developed an OTR monitor for the
precise measurement of injected beams.
(3) Noise reduction of Current Transformer
The noise level of a CT near an injection
point of the ring, which was affected by pulse
magnets such as bump and septum, wasreduced.

(4) Upgrade of tune measurement system
By introducing an inexpensive USB-typereal-time
spectrum
analyzer,
betatronfrequencies of electron beams (tunes) could bemeasured with higher accuracy and higher
update speed than before.
Development of Camera Control and Image
Processing Systems for Profile Monitors
1.0 GeV electron beams are injected fromthe SPring-8 Linac to the NewSUBARU ring
through the L4BT beam transport line. To
measure position and size of injected beams,
five profile monitors (M1~M5) using afluorescent screen have been used at L4BT.
We developed a camera control system that canremotely adjust to the optimum setting for eachcamera from a PC in the control room as shownin Fig. 1.
We also developed an image processing
software, which can measure beam size andposition from the observed fluorescence (Fig.2).
Because fluorescence was observed by visualFig.2 Profile monitor image processing
software developed using LabVIEW.

Fig.1 Layout of the image processing andcamera control system for L4BT profile
monitors.

observation using a TV monitor previously, themeasurement accuracy has been greatly
improved.

11

measurement makes it possible to optimize
parameters of the L4BT for ideal transport ofelectron beams.

Introduction of OTR Monitor to L4BT BeamTransport Line
Because fluorescence light is very bright, it
is easily observed but the measured beam size isoften over-estimated.
In general an OTR(optical transition radiation) monitor is often
used in the precise beam measurement in abeam transport and a Linac. When an electron
passes through a thin metal film such as Al, due
to an abrupt change in dielectric constant, atransition radiation is emitted in a broadband
frequency range (Fig.3).
We installed an OTR monitor at the upstreamof the L4BT. A GigE camera observes a weak
OTR light in an optical region. The OTR lightis a very short pulse, so the camera is triggeredby a timing signal. Fig. 4 shows the horizontal
and vertical beam sizes measured using the OTR
monitor. For comparison, the measurement
data using the fluorescence monitor (M5) in theimmediate vicinity of the OTR monitor. It was

Noise reduction in a Current Transformer(CT3) signal
The intensity of the beam passing throughthe L4BT line can be non-destructively
measured using current transformer (CT). In
the L4BT, three CTs are used as show in Fig. 5.
The CT closest to the ring (CT3) has sufferedfrom severe noises in measured signal, whichcome from pulsed magnets such as bump andseptum through a vacuum chamber and a girder.
Thus we have been using CT1 located far fromthe ring for evaluating beam injection efficiency.
As a result of trial and error, we succeededin suppressing the noise in CT3 as shown in
Fig.6. Before noise countermeasure, the noise
intensity was about 70 mV in peak-to-peak.
By short-circuiting the downstream of the CT
and the vacuum pipe, a ground level fluctuation
was canceled and noise disappeared. This
made it possible to precisely measure beam
intensity just before the ring and to calculate
injection efficiency accurately.

Fig. 3 Transition radiation
Fig. 5 Layout of the beam injection point of
the NewSUBARU ring.

Fig. 4 Horizontal and vertical beam sizes
measured by the profile monitor (M5) and the
OTR monitor.

Fig. 6 Reduction of noise in beam signal
measured by CT. Before (left) and after(after) the noise reduction.

found that the beam sizes measured using the
OTR monitor are about 75% smaller than thoseof M5 monitor.
The exact beam size

Upgrade of Tune Measurement System
While stored electrons circulate in the ring,each electron oscillates in both horizontal and12vertical directions around a stable closed orbit(betatron oscillation).
The number ofoscillation per ring circumference is called tunes.
For stable operation of the ring, tunes should be
kept to the optimum values.
The former tune measurement system wasbased on PXI platform and could measure tunes
with high accuracy. However, because thesystem performed FFT of an acquired waveform
data in a PC, it took time to update the data andwas not suitable for high-speed measurement.
In the newly developed system, adifferential signal from two electrodes at
diagonal positions in one beam position monitor
is analyzed in frequency domain using aspectrum analyzer (Tektronix RSA306B). This
compact device transferred .the FFT waveform
to a PC through USB-3.0 and signal

Although our facility has lower maintenancecost and lower manpower, we have beenworking on improving accelerator equipment.
The upgrade of measurement systems on
beam injection contributes to a recent stable
operation. The tune measurement with highprecision and high speed is useful to the
reduction of beam instabilities. Stack of small
improvements is necessary for the stable
operation of a huge device.
References[1] A.Ando et al., J. Synchrotron Rad., 5, 342-344(1998)[2] http://www.lasti.u-hyogo.ac.jp/NS-enprocessings such as smoothing, curve-fit,
peak detevtion, error handling are
performed in an application softwaredevelopped using LabVIEW.
Tune
resolution is about 0.0001 and update period
is less than 200ms. A smart algorithm wasalso developped to exclude incorrect results
due to a temporal waveform distortion
during beam injection, energy ramping.
This tune measurement system withhigher update speed and higher accuracy
could measure a dynamic change of tunes
and is useful to reveal beam dynamics in thering. Currently, a real-time tune correction
system is under development, which will
corect tune shift caused by various factors.

Fig.7 Real-time tune measurement system using USB-type spectrum analyzer.

Summary

13

Broadband vacuum ultraviolet lightsfrom solid rare-gas plasmas
Sho Amano
LASTI, University of Hyogo

Abstract

The laser plasma emission spectra in a broadband from 30 to 200 nm of solid Ar, Kr, and Xe
targets are presented for the first time. The spectra are composed of a broadband continuum andlines. The spectral intensity integrated from 30 to 200 nm indicates that the VUV average power
generated in the wavelength range is 30 mW when the laser energy is 1 J at 1 Hz. The number ofphotons of monochromatic light after passing through the spectrometer is estimated to be morethan 5×106 photons/nm/pulse over the wavelength range and is considered to be useful for
applications of broadband VUV spectroscopy.

Introduction
Vacuum ultraviolet (VUV) light, whose
photon energy is sufficient for ionizing most
molecules, interacts strongly with matter. VUVlight is therefore useful in many research areas
such as surface physics, chemistry, and biology.
As VUV light sources, a deuterium discharge
lamp, an excimer lamp/laser or the highharmonics of an IR laser have been used, but
their emission wavelengths are fixed and lackcontinuous and wide tunability. However, awidely tunable VUV light source is required inspectroscopy experiments for various material
studies. A synchrotron radiation (SR) source isversatile for having continuous tunability over awide range of VUV to X-ray, but it is notsuitable for a small laboratory or a factory,owing to its large size and high cost. Therefore,
laser plasma sources that are compact andinexpensive compared with the SR source havebeen studied to achieve continuously tunable
VUV light [1,2].
We have been studying laser plasma sources
using solid rare-gas targets that can generatecontinuously repetitive pulses on a long-termbasis [3]. To study the characteristics of VUVemissions from the targets, we developed a
VUV spectrometer that could measure thebroadband VUV spectra in the wavelength rangeof 30 to 200 nm. Measurement results showedbroadband continuous spectra in the 30–200 nm
range from the solid Ar, Kr, and Xe targets,
which are the first reports as far as we know. In
this paper, we report the VUV characteristics
from the solid rare-gas targets including themeasured spectra. Finally, we evaluate its
performance for VUV spectroscopy.

system was described in detail previously [4].
Nd:YAG Laser(SP;
PRO-230)
Nd:YAG
Laser(SP;
PRO-230)
1064nm/10ns
1064nm/10ns
Max1.0J/1Hz
1.0J/1Hz

X-ray CCDVUV Spectrometer

X-ray CCDVUV Spectrometer

VM502

VM502

Lens

Lens

Window
Window

TargetsystemsystemTarget(AXUV100G+126nmBPF)
XRD(AXUV100G+126nmBPF)
XRD

VacuumVacuumchamberchamberFig. 1. Experimental setup of the laser plasma VUVsource (top view).
To measure the VUV energy generated, an X-ray
diode (XRD) (OptoDiode, AXUV100) was located at
45° to the axis of the incident laser beam. A band-passfilter (Acton, 126-N-1D), with transmission in therange from 110 to 200 nm, was placed in front of thediode. To measure the VUV spectra, a VUVspectrometer was located tangentially with respect tothe target surface. The spectrometer consisted of acommercial VUV vacuum monochromator (Acton,
VM-502-V) and a back-illuminated two-dimensionalcharge-coupled device (CCD) (Princeton, PI-SX400).
The VUV vacuum monochromator contained aniridium-coated grating with a 1200 lines/mm pattern,which covered a range of more than 30 nm, and its
focal length and resolution were 200 mm and 0.1 nm,
respectively. The exit slit was removed from the VUVvacuum monochromator and the CCD was attached toposition its surface at the focal point of the grating.
The CCD could record one spectrum from a single
shot plasma by triggering an external laser signal.
Results & Discussion
The spectral intensity was calibrated absolutely
using the XRD data. The absolutely calibrated
emission spectra in the VUV region (30–200 nm)
from the solid Ar, Kr, and Xe targets are shown in Fig.

Experiments

Figure 1 shows the experimental setup of the laser
plasma VUV light source, composed of a target supply
system and a driving laser. The developed target

142. This is the first report of such broadband VUVspectra from solid Ar, Kr, and Xe, as far as we know.
The irradiated laser energy was 1 J and the laser
intensity was 5×1012 W/cm2. These spectra for all
targets show that the broadband continuums in the 30–
200 nm range and many peaks, which can be
attributed to the transitions of charged ions andneutrals. The vertical axis represents the spatiallyintegrated energies generated from the targets at eachwavelength. The spectra were also time-integrated andinvolved both fast excitation and slow relaxation
processes. In the fast excitation process when the very
hot and dense plasma was produced during the laser

pulse irradiation, free-free radiation (Bremsstrahlung
radiation) and free-bound electron recombination werethe main mechanisms and contributors to the spectral
continuum. In the slow relaxation process when the
expanded and relaxed plasma was produced after thelaser irradiation, bound-bound electronic transitions ofions and neutrals were the main mechanism andcontributors to the spectral lines. Figure 2 indicatesthat the generated VUV energy integrated in the 30–
200 nm range was roughly the same (approximately
30 mJ) for all the solid Ar, Kr, and Xe targets. Because
the laser repetition rate was 1 Hz, the VUV average
power obtained was approximately 30 mW.

Fig.2 VUV emission spectra in the ranges of 30 to 100 nm (upper) and 100 to 200 nm (lower) from the solid Ar(left), Kr (center), and Xe (right) targets. The vertical axis represents emission energy integrated in total space
and time per wavelength. The laser energy was 1 J and the laser intensity was 5×1012 W/cm2.
Finally, we considered the number of photons ofmonochromatic light after passing through thespectrometer, which could actually be used forspectroscopy. To increase the number of photons asmuch as possible, we reset the spectrometer at 45° tothe axis of the laser beam incidence and measured thespectra again. The spectral shape did not change, but
its intensity increased by one order of magnitude
compared with that obtained with the initial setup. In
the measurement, the number of photons on the CCD
was calculated to be more than 5×106
photons/nm/pulse over the 30–200 nm range using the
CCD sensitivity, when the laser energy was I J at 1 Hz.
The number of photons depends on the distance
between the spectrometer and the plasma, for example,
more than 1×108 photons/nm/pulse can be obtained
when the spectrometer is placed close at 150 mm. The
number of photons is considered to be useful for
applications of broadband VUV spectroscopy and isparticularly sufficient for photon counting andone-photon ionization spectroscopy. In conclusion,

15

our laser plasma VUV sources using solid rare-gas
targets are unique sources that can emit a broadband
continuum with wide tunability and can be operated
continuously.
Acknowledgments
This work was supported by JSPS KAKENHI (Grant
No. 23654204).

References[1] T. M. Di Palma and A. Borghese, Nucl. Instr. andMeth. B 254, 193 (2007).
[2] M. Kaku, T. Yamaura, T. Higashiguchi, S.
Kubodera, and W. Sasaki, Jpn. J. Appl. Phys. 42,3458 (2003).
[3] S. Amano, Appl. Phys. Exp. 9, 076201(2016).
[4] S. Amano, Rev. Sci. Instrum. 85, 063104(2014).

Mechanical stability of the main axis of double multilayer
film monochromator by change of Bragg angles in BL07A
Masato Okui1, 2, Naoki Yato1, Ren Konno1, Akinobu Watanabe1, Sei Fukushima2, 3 and Kazuhiro Kanda2
1. Kohzu Precision Co., Ltd. 2. LASTI, University of Hyogo, 3.Kobe Material Testing Laboratory Co., Ltd.

Abstract

The mechanical stability of the main axis with elapsed time is one of the basic factors to achieve
high stability of beam position from monochromators. The authors have been made preliminary
experiment by using BL07A, NewSUBARU to improve the more mechanical of the main axis. In
this experiment, the stability of the Bragg angle of its monochromator was measured by a ring
scale encoder, when the Bragg angle was 10 degrees and 20 degrees, respectively. The results leadto the possibility that the axis would be drift largely when the Bragg angle is about 20 degrees orupper. This possibility shall lead the necessary that we should produce the new design and newconcept for a monochromator and the concept should be the geometry of a monochromator withkeeping perfect balance whatever Bragg angle.

Introduction
Recently, the beam size of synchrotron tends
to smaller than the previous. Thus, the opticalstability that is beam position change by timefrom upstream monochromators would be
important than the previous them. This opticalstability from monochromator would be caused
by various factors, but the mechanical stabilityof the main axis with elapsed time is one of thebasic factors to solve this optical stability
problem.
The authors have been made a preliminary
experiment by using Kohzu MKZ-7NS type
double multilayer films monochromator set upon the BL07A to improve the more mechanicalstability of their main axis.
And in the last year annual report [1], thepossibility of mechanical slight drift waspointed out by observation of ring scale encoder.
In this report, the preliminary experiment has
been continued in this year.
The new facts about the mechanical stabilityof the main axis in the monochromator wasgotten and the reappearance of the last year 's
experiment was gotten too.

Fig.1. Photograph of MKZ-7NS type
double multilayer films monochromator.

Fig. 2. The schematic system drawings of
MKZ-7NS type monochromator.
The experiment was made when the storage
ring energy was 1.5GeV, then, the ID gap tuned
as 48.3mm after the injection.
The Bragg angle was 10 degree and 20 degree,
respectively and the other axes were tuned foreach main axis angle. After these tuning, thedata of mechanical stability of the main axis
theta had been collected.
In during the measurement, the motor pulseof the pulse motor was fixed after the
positioning not to move all axes from thepositions tuned. The output pulse of the ring
scale encoder (Heidenhain RON886) wasrecorded, and during the experiment the authors
checked keeping still each motor pulse values

Experimental
As well as the previous study, the present
experimental has been made by using
MKZ-7NS type double multilayer films
monochromator set up on BL07A in
NewSUBARU. This specification of themultilayer films monochromator has alreadybeen reported by Okui et al., [2] [3].
Fig. 1 shows the photograph of panoramicview of MKZ-7S type monochromator. The
schematic system drawings of MKZ-7S type
monochromator is shown as Fig. 2.

16

from the initial values.
Result and Discussion
Result of experiment is shown as Fig.3. In
the figure, the vertical axis shows relative thepositional displacement from the initial positionof the main axis θ, Bragg angle after the all axes
tuned and the horizontal axis shows the elapsed
time since starting each experiment.
The Orange circle and line shows therelative position displacement by elapsed time
when the Bragg angle is 10 degrees. As well as
the above, blue circle and line shows the relative
positional displacement by elapsed time whenthe Bragg angle is 20 degrees.

Fig.4. The schematic design drawing of
MKZ-7NS type monochromator.
The rotation center of main axis is on thefirst monochromatic devise, and only Z2 axis go
far side when Bragg angle go to higher side.
Thus, it is possibility that the center of gravity isslightly different from rotation center when the
Bragg angle is high.
This suggestion shall lead the necessarythat we should produce the new design and it
would be new concept for next generation
monochromator and the concept should be theoptical geometry of a monochromator keeping
perfect balance whatever Bragg angle. For
satisfaction with the optical geometry, it isneeded that the control system with integrated
computing using computing electronic cam.

Fig. 3. Mechanical stability of the main axis
θ of MK-7NS type monochromator set on
BL07A in NewSUBARU.
In this graph the blue circle and line showsthe10 degrees case and Orange circle andline shows the 20 degrees case.

The authors had the presentation of thiselectronic cam technology for this monochromator in AnalytiX-2018, Florida, USA in
March 2018.

Surprisingly, the curves of the relative
displacement of the main axis is different
between the 10 degrees Bragg angle case and 20
degrees case remarkably in this experiment. The
10 degrees curve is slightly up by elapsed time
but almost have kept the initial value, but the 20
degrees curve have been remarkable down by
the elapsed time.
The previous study [1] would be made with
Bragg angle is 24.19 degrees. the previous resultshows a similar curve as the present 20 degrees
curve.
From these results, it would be suggested thepossibility that the positional drift by the elapsed
time of the main axis in MKZ-7NS type
monochromator would depend on the Bragg
angle. The authors would like to propose thepossibility that the axis would be drift largely
when the Bragg angle is about 20 degrees orupper.
The schematic design drawing reported by
Okui et al. [3] is shown as Fig.4.

Acknowledgement
The authors thank for support by the project
members of the development of next generation
monochromator in Kohzu Precision Co., Ltd.
References[1] Okui et al., LASTI Annual Report, 18(2016),
15-16. (2017).
[2] Okui et al., LASTI Annual Report, 17(2015),
15-16. (2016).
[3] Okui et al., AIP Conference Proceedings
1741, 030033, (2016).

17

Part 2. Research Activities

Dr. Nobukazu Teranishi, guest professor of LASTI, became the firstJapanese to win Queen Elizabeth Prize for Engineering in 2017
（Source: http://qeprize.org/photo-gallery/qeprize-presentation-2017/）

Photoneutron cross-section measurements on 209Bi for the
IAEA CRP on updating the photonuclear data library
I. Gheorghe1, H. Utsunomiya2, the Phoenix* Collaboration
ELI-NP, "Horia Hulubei" National Institute for Physics and Nuclear Engineering,
30 Reactorului, 077125 Bucharest-Magurele, Romania
2
Konan University, Department of Physics, Okamoto 8-9-1, Higashinada, Kobe 658-8501, Japan
1

Abstract

The Phoenix Collaboration aims to provide new data of total and partial (γ, xn) cross sections with
x=1-3 for 11 nuclides to the IAEA (International Atomic Energy Agency)-CRP (CordinatedResearch Program) F41032 on updating the photonuclear data library. For the first measurement
within the project, the total and partial photoneutron cross sections for 209Bi have been investigatedin the energy range of 7.7 – 42.2 MeV using the quasimonochromatic Laser Compton scattered
γ-ray beams provided by the γ-ray Beam Line 1 of the NewSUBARU facility. (*Photoexcitationand neutron emission cross (x) sections.)

Introduction
A new coordinated research project has beenlaunched by the IAEA to update the current
photonuclear data library [1]. One of its main
objectives is to provide new total and partial
photoneutron cross sections for selected nuclei
to resolve the longstanding discrepancies
between the Livermore and Saclay data [2].
The Phoenix Collaboration between the
Konan University of Kobe, the Skobeltsyn
Institute of Nuclear Physics of the Lomonosov
Moscow State University and the Extreme Light
Infrastructure-Nuclear Physics (ELI-NP) aims tomeasure the total and partial (γ, xn) crosssections with x=1-3(4) for 209Bi, 9Be, 197Au,
181
Ta, 139La, 169Tm, 165Ho, 159Tb, 103Rh, 89Y and59
Co.

the laser beam intensity with an additional
optical system comprised of a Pockels cell and apolarizer which blocked seven out of eight
consecutive laser pulses.

Fig.1 The LCS γ-ray Beam Line 1.
The γ-ray beam energy spectrum wasmonitored using a large volume lanthanum
bromide (LaBr3:Ce) detector. Energy resolution
values between 1.6% and 3.2% in FWHM wereobtained for the high energy γ-ray beams, above
the S2n. The γ-ray beams below the S2n showed abroader energy spread of 4%–7%. The energy
spectra and the average path length through thetarget per incident photon histograms are
displayed in Fig. 2 for each of the γ-ray beams.

Experiments and Results
Photoneutron cross-section measurements
were performed in 209Bi(γ, xn) reactions with
x=1–4 using Laser Compton scattered (LCS)
γ-ray beams at the Beam Line 1 of the
NewSUBARU synchrotron radiation facility[3].
A schematic diagram of the experimental setup
is shown in Fig. 1.
The high-power Nd:YVO4 laser INAZUMA(Spectra-Physics) was used in the first (λ = 1064nm) and second (λ = 532 nm) harmonic toproduce LCS γ-ray beams with maximum
energies between 7.7 and 42.2 MeV. The beamirradiated a 209Bi target placed at the center ofthe flat efficiency neutron detection system [4]comprised of 3He counters embedded inpolyethylene moderator block.
The laser was operated in Q-switch mode at
16.66 kHz frequency, corresponding to 60 μs
between consecutive laser bunches. The 60 μs
interval was extended to 480 μs by modulating

Fig.2 The energy spectra and the averagepath length through the target per incident
photon for each of the incident LCS γ-ray
beams.
Above S2n, the number of events in which
only one (single N1 ), only two (double N2),
only three (triple N3), and only four (quadrupleN4 ) neutron events were recorded, were
determined from the neutron moderation time21

model as well as by a Simplified version of themodified Lorentzian (SMLO) approach. We
represented both the exclusive (γ,xn) channels
and the inclusive (γ,xn)+ (γ,xnp)+ (γ,xna)+…
ones. The present 209Bi(γ, tot) cross sections
obtained as the sum of the partial cross sections
are displayed in Fig. 5 along with existing
experimental results and evaluations and
EMPIRE calculations.

Fig.3 Neutron moderation time spectra of (a)single, (b) double, (c) triple, and (d) quadruple
neutron events generated in 209Bi(γ, xn)
reactions induced by 42.2 MeV maximum
energy LCS γ-rays. The experimental time
spectra (solid black) are displayed along withthe corresponding best fit (solid blue). The fit
functions for reaction neutrons (dashed)produced by the main γ-ray bunches and thebackground (dotted) contributions are displayed
separately.
spectra. Figure 3 shows examples of neutron
time moderation spectra for single, double,
triple, and quadruple events, respectively. The
direct neutron multiplicity sorting techniquedescribed in Ref. [4] was applied to obtain thenumber of 209Bi(γ, xn) reactions with x = 1–4.
The monochromatic cross sections werecorrected by taking into consideration theprobability of multiple firing events, in whichmore than one photon from the same LCS γ-ray
beam bunch induces photoneutron reactions in
the target. The corrections are necessary where
there is a considerable difference between the
cross sections of competitive reaction channels.
An energy unfolding procedure has been
performed on the monochromatic cross sections.
For each irradiation point, the average path
length through the target per incident photon has
been constructed using Geant4 simulations, inwhich the energy spectra of the LCS γ-ray
beams and the physical dimensions of theirradiated targets are given as input. The
unfolding procedure consists in iteratively
adjusting a test cross section until the folding
between it and the incident photon spectrum
reproduces the monochromatic cross sections.
The partial 209Bi(γ, xn) with x=1-4 crosssections are compared in Figure 4 withstatistical model calculations performed with the
EMPIRE code. The GDR component wascalculated by a standard Lorentzian (SLO)

Fig.4 Present results of 209Bi(γ,xn) with
x=1-4 cross sections compared with statisticalmodel calculations performed with the SLO (redcurves) and SMLO (blue curves) gamma
strength functions.

Fig.5 Present results of 209Bi(γ,tot) crosssections compared existing experimental results
and evaluations and EMPIRE calculations.
References[1] IAEA Coordinated Research Project on
Photonuclear Data and Photon Strength
Functions,
https://www-nds.iaea.org/CRP-photonuclear/.
[2] B. S. Ishkhanov et al., Phys. At. Nucl. 67,
1664 (2004).
[3] I. Gheorghe et al., Phys. Rev. C 96, 044604(2017).
[4] H. Utsunomiya et al., Nucl. Instrum.
Methods A 871, 135 (2017).

22

Development of positron annihilation apparatus for defects
study in bulk materials using BL01 gamma ray
K. Sugita1, S. Miyamoto2, M. Terasawa2, F. Hori1
Osaka Prefecture University, 2 LASTI, University of Hyogo

1

Abstract

We have developed a new positron annihilation apparatus as direct implantation of Laser Compton
scattering (LCS) gamma rays, which are derived at NewSUBARU beam line BL01, into bulk
materials. By using this method, we have measured positron annihilation Doppler broadening
spectra of bulk silicon and bulk iron before and after electron irradiation. LCS gamma ray
maximum energy of 16.9 MeV using by Nd:YVO4 laser and 982 MeV electron are injected
directly into samples, caused pair creation and annihilation gamma ray emission in the samples.
Positron annihilation gamma rays as the energy spectra were detected by HP-Ge detector. Doppler
broadening spectra measured by this method is consistent with other measurement results ofpositron annihilation by using 22Na radioactive source.

Introduction
Positron annihilation methods are used
defect study in materials widely. Positron source
usually use for defects research is mainly
radioisotope (RI). Positron from RI are notmono-energetic and about several hundred keV
in maximum so that it can be estimated only
near surface in materials. In order to detect
defects in mm depth of bulk materials with
nondestructive, more than MeV ordered positronis needed. Therefore, we have constructed a newpositron apparatus using high energetic positroncreated via pair creation from Laser Compton
scattering (LCS) gamma rays at BL01 [1-2]. Theenergy of LCS gamma rays at this beam line isextremely high and controllable. We have now
developing a new positron measurement system
by using this LCS gamma ray. That is, both thepair creation and annihilation take place in thesample by implantation of this gamma ray into asample directly. Detected annihilation gamma
ray is analyzed the energy distribution of
positron annihilation Doppler broadening. In
this report, the measurement result of somedifferent materials by this positron annihilation
method are demonstrated.

Positron annihilation apparatus setup
Figure 1 shows the system of LCS gamma
source at BL01. LCS gamma ray irradiated andpositron annihilation experiment in hutch-2
GACKO. LCS gamma ray is produced byscattering between laser photon and circling
electron in storage ring. Energy of LCS gamma
ray is determination laser wavelength andelectron energy [3]. Injection laser photon andcircling electron is head on collision in Figure 1.
Generated gamma ray passes through thevacuum duct and two lead collimators T and H,
and finally reaches the optical hutch-2 GACKO.
LCS gamma ray with maximum energy of 16.9
MeV generated from Nd:YVO4 laser ( =) and circulated electron with the1064
energy of 982 MeV. In this case, diameter of 6
mm two Pb collimators were used, therefore,
LCS gamma ray minimum energy was 15.2
MeV at the BL01 setup. LCS gamma ray isimplanted into a sample and annihilation gamma
rays are detected in hutch-2. Figure 2 shows theschematic setup the positron creation andannihilation in sample system. Annihilation
gamma rays detected by HP-Ge detector whichis covered by Pb blocks. This gamma ray with

Fig.1 LCS gamma ray system at NewSUBRU BL01.

23

this energy is high enough to transmit mm
thickness bulk samples as shown in figure 3.
This figure shows that simulation of gamma
tracks and created positron tracks by
implantation of 16.9 MeV LCS gamma ray into
iron calculated by PHITS code version 3.02
based on the Monte Carlo simulation [4]. As canbe seen in this figure, positrons are createdhomogeneously on gamma ray tracks.

measured as irradiated sample. Positron creation
and annihilation takes place on the gamma
tracks homogeneously, hence observed positronparameters show average information in a wholesample. Figure 4 shows positron annihilation
Doppler spectra in all samples. The spectra for
Si and Fe show different peak height dependingon their different electron distribution in thesesamples. Peak height of positron annihilation
Doppler profile in Si is higher than in Fe, whichis consistent with the results of general positronannihilation measurement for Si and Fe by using
22
Na as a positron source. On the other hand, it
seems slight difference between iron samples
before and after electron irradiation. This isbecause the average of positron annihilation
events in an irradiated and non-irradiated ironplates. Table 2 shows S parameters of thesesamples. In this figure, S parameter for
irradiated sample is larger than that for
non-irradiated one. This result shows that
extremely low concentration of vacancy typedefects introduced by electron irradiation was
successfully detected by this method.

Fig2. Schematic illustration of positron creation
and annihilation by direct LCS gamma ray
implantation apparatus.

Table 1. Sample conditions.

Samplepure Fe (4N)
electron irradiated Fe(8MeV, 1 x 1018/cm2)+ pure Fe (4N)
Si (Cz-Si)

size
20mm x 50 mm x 5mm

20mm x 50 mm x 2mm+ 20mm x 50 mm x 3mm
20mm x 45mm x 16.5mm

Fig3. Simulation of 16.9 MeV LCS gamma
ray implantation into Fe calculated by
PHITS code. (a) gamma ray tracks in ironand (b) created positrons.
Fig4. Positron Doppler profiles in all samples.

Measurement
We have measured Doppler broadening
spectra for pure silicon, pure iron and 8 MeV
electron irradiated iron by this positronannihilation system. Table 1 shows the size ofall samples. Pure samples are well annealed, andelectron irradiation have performed by linear
accelerator at Kyoto University Reactor
Research Institute with fluence of 1 x 1018/cm2.
In this case, electron irradiation introduces
vacancy type defects with about 100 at.ppm into
iron. However, an electron irradiated ironsample is thinner than non-irradiated one, thenpiled it on a non-irradiated iron plate wasTable 2. S parameter of sample.
Samplepure Feelectron irradiated Fe+ pure Fe

S parameter
0.566
0.571

Reference[1] F. Hori et al., Jpn. J. Appl. Phys. conf. proc.2
011301 (2014).
[2] F. Hori et al., J. Phys. conf. Ser. 674 (2016)
012025.
[3] C. Sun and Y. K. Wu., Phys. Rev. ST Accel.
Beams 14, 044701(2011).
[4] Tatsuhiko Sato et al., J. Nucl. Sci. Tecnol. 55,
684-690(2018).

24

Measurement of deflection on germanium and gold prisms
using 1.7 MeV laser Compton scattering γ-rays
T. Kawasaki1, S. Naito1, Y. Sano1, T. Hayakawa2, T. Shizuma2, R. Hajima2, and S. Miyamoto3
Toshiba Corporation, 2 National Institutes for Quantum and Radiological Science and Technology,
3
University of Hyogo

1

Abstract

The refractive indexes δ of Ge and Au prisms for γ-rays at 1.7 MeV were measured to explore if
there are refractive index enhancements to 6th power of atomic number due to high ordernonlinear process of Delbrück scattering by using Laser Compton scattering (LCS) γ-rays at BL01,
NewSUBARU. The measured upper limit of δ for crystal Ge, crystal Au or polycrystal Au prisms
are 4.010-8, 2.910-7, or 2.410-7, respectively. This result does not support the hypothesis of thehigher order Delbrück scattering suggested by Habs et al. [Phys. Rev. Lett. 108, 184802 (2012)].

Introduction
The refractive index |δ(Eγ)| following Snell’s law
is given by n(Eγ) = 1+δ(Eγ)+iβ(Eγ), where Eγ, δ,and β are photon energy, phase shift affecting lightdeflection, and extinction coefficient affecting lightabsorption, respectively. Typically, |δ(Eγ)| in anenergy region above 1 MeV should be less than theorder of 10-10
On the other hand, Habs et al. found that therefraction index δ of a silicon prism was on theorder of 10-9 which is higher than the predictedvalue by an order of magnitude at energies above
0.7 MeV [1]. They presented that the enhancement
can be explained by higher order terms of Delbrück
scattering with Z4 and Z6 dependence, where Z is
atomic number. According to this hypothesis, therefraction of γ-rays has a strong dependence of theatomic number Z and the δ becomes approximately
10-5 at Z = 79 (Au). This value would be possible to
make refractive optics for γ-rays in the MeV energy
region, which would enable new experimental
techniques for nuclear physics [2] and γ-ray
astronomy [3].
In this experiment, we measured the refractive
index of Ge (Z=32) and Au (Z=79) prisms using
imaging plates (IP) with 1.7 MeV LCS γ-ray beams
at the BL01 beam line in the NewSUBARU [4].
Experimental Procedure
Figure 1 shows experimental setup at BL01. The
γ-ray beam was generated by Compton scattering of
1 GeV electrons and 10.6 µm CO2 laser beams at
the collision point [5]. The prisms were locatedinside the first experiment room, whereas the IP and
NaI(Tl) detector were set inside the second
experiment room. The approximate distance fromthe collision point to the prisms and from the prisms
to the IP were 10 m and 8m, respectively. The peakenergy of the γ-ray beam measured by NaI(Tl)detector was 1.7 MeV.
δ(Eγ) was evaluated from the displacement of a
γ-ray beam passing through the prisms by

Fig.1 Experimental setup at BL01(c)Fig. 2 Shape of prisms. (a) Au and Ge single
crystalline-prism. The lengths l and angles θ ofAu (Ge) prims are 6 mm and 77º (12 mm and83.5º), respectively. (b) Au polycrystalline prism(c) Au single-crystalline prism.
measuring the γ-ray distribution with the IP*. An IP
reader (BAS-2500, FUJIFILM)* with a spatial
resolution of 50 µm was used as a reader.
In principle, the cross section of the Delbrück
scattering depends on the angle of scattering planeand polarization [6]. Therefore, to investigate thecorrelation between δ and linear polarization planeangles, we used p- and s-polarized γ-rays for the Au
single-crystalline prisms. The evaluated linearity ofthe γ-rays polarization from that of the CO2 laser
was 99.5%. In addition, we also used unpolarized
beams to compare with the previous experiment [1]measured by using unpolarized γ-ray generated byneutron capture reactions.
In this experiment, we chose Au (Z=79) and Ge(Z=32) as prism materials that have Z larger thanthat of Si measured by Habs et al. [1]. The large Z* Product names mentioned herein may be trademarks of their respective companies.

25

of Au should produce a large effect on δ, due to theZ6 dependence. The Ge crystal has diamondstructure as same as that of Si. In term of Z andcrystalline, we fabricated three types of prisms withmirror finish surface: Au single-crystalline prisms,
Au polycrystalline prisms, and Ge single-crystalline
prisms as shown in Fig. 2. The Au single-crystalline
prisms were a cube 6 mm on a side and were tilted
at an angle of 77º to the γ-ray beam axis. The Au
polycrystalline prisms were pentagonal and both theincident and output angles were 77º to the γ-ray
axis. The Ge crystal prisms were a cube 12 mm ona side and were tilted at an angle of 83.5º to theγ-ray axis. The γ-ray beam entered the verticalcenter of the each prism’s planes.
To increase the small deflection angle, 18 Ge
single-crystalline prisms, 5 Au single-crystalline
prisms, or 3 Au polycrystalline prisms werearranged. From the previous study [1], δ of Si(Z=14) was 10-9 for 1.7 MeV γ-rays. Therefore, if
this enhanced δ is dominated by the term
proportional to Z6, the expected refractive index for
Ge (Z=32) δGe and for Au (Z=79) δAu are(32/14)610-9 = 1.410-7 and (79/14)610-9 =3.210-5, respectively. According to these value andSnell’s law, the expected displacement between theincident and the deflected γ-ray beam on the IP for
the Ge single crystals, Au single crystals, or Au
polycrystalline prisms should be 1.6102 μm,
5.9103 μm, or 6.7103 μm, respectively.
As shown in Fig 1, the collimator has two slits
with height of 0.5 mm and width of 2 mm that werehorizontally arranged at 1 mm interval. One of thetwo beams separated by the collimator passes
through a prism set and subsequently irradiated theIP, whereas the other beam directly irradiated the IP
without passing through prisms to be used as anindex beam to estimate relative displacement. To
obtain the image of the only LCS γ-rays, we also
subtracted the IP image of only bremsstrahlung
x-ray obtained with the CO2 laser-off from theimage with the CO2 laser-on.

the expected values if the Z6 dependence exists.
Significant difference between the upper limits ofsingle-crystalline and polycrystalline prisms for Au
are also not observed. In addition, there is nodifference among unpolarized, p-polarized, ands-polarized γ-rays. In this way, we cannot find any
signature for the enhancement proportional to Z6.
CONCLUSION
In order to explore a strong Z dependence ofrefractive index proportional to Z6, which may
originate from the nonlinear effect in Delbrück
scattering, we measured the displacement at 8 m
downstream of Au or Ge prisms for 1.7 MeV LCS
γ-rays. The measured upper limits of the refractive
index of δGe, δAu,single, and δAu,poly are 4.010-8,
2.910-7, and 2.410-7, respectively. However, we
could not find any evidence that such process occurs,
which can contribute to realize the optical device for
γ-rays in the MeV energy region. This result does
not support the hypothesis suggested by Habs et al.
[1]. Because we investigated only the Z6 dependence
in the present study, the reason for the δenhancement [1] has remained an open question.
Acknowledgements
This work was supported by JSPS KAKENHI
Grant Number 15H03665.
References[1] D. Habs et al., Phys. Rev. Lett. 108, 184802(2012).
[2] P.G. Thirolf et al., EPJ Web of Conferences 38
08001 (2012).
[3] B. C. Lacki et al., Astrophys. J. 786, 40 (2014).
[4] T. Kawasaki et al., Phys. Lett. B. 381, 3129
(2017).
[5] S. Amano et al., Nucl. Instrum. Methods Phys.
Res., Sect. A 602, 337 (2009).
[6] J. K. Koga, and T. Hayakawa, Phys. Rev. Lett.
118, 204801 (2017).
[7] H. Hirayama et al., SLAC Report number:
SLAC-R-730(2004)

RESULT AND DISCUSSION
Figure 3 shows measured image of γ-rays. The
intensity was integrated along x- axis to estimate the
distribution and displacement along y-axis.
Figure 4 shows the experimental results and theFig. 3 γ-rays measured by IP
results calculated by “EGS5” [7]. The calculattion
does not include the Delbrück scattering. However,the vertical peak position of each measurement
result is not different from the corresponding
calculated result within 50 μm error. According tothis resolution of 50 μm, the upper limits of therefractive index of δGe, δAu,single, and δAu,poly are
4.010-8, 2.910-7, and 2.410-7, respectively. These
Fig. 4 Experimental result of Au single
upper limits are 1-2 orders of magnitude lower than crystalline prism with p-polarized γ-rays

26

XAFS Measurements in the Soft X-ray Region
around 1 keV in BL05A
T. Hasegawa1, 2, 3, S. Fukushima1, 2, 3 and K. Kanda3
1 Synchrotron Analysis L.L.C., 3-2-24 Wadamiya-dori, Hyogo-ku, Kobe-shi, Hyogo 652-0863 Japan
2 Kobe Material Testing Laboratory Co., Ltd., 47-13 Niijima, Harima-cho, Kako-gun, Hyogo 675-0155 Japan
3 LASTI, University of Hyogo, 3-1-2 Koto Kamigori-cho, Ako-gun, Hyogo 678-1205 Japan

Abstract

BL05A is a unique double crystal monochromator (DCM) beamline of NewSUBARU and is used
for X-ray absorption fine structure (XAFS) spectroscopy. We have applied the DCM that consistsof crystals of Beryl and KTP to cover the X-ray energy range lower than that of the InSb crystal.
Furthermore, we have successfully improved efficiency of X-ray transmission by using aberyllium filter with thickness 25 m in this energy region. Consequently, this setup hasenabled practical analysis in the soft X-ray region around 1 keV. In addition, we conducted theevaluation of the radiation damage of the KTP crystal and confirmed that the intensity of
Bragg reflection was decreased.

the filter of thickness from 45 m down to 25
m[3, 4, 5]. In addition, in order to cover the
lower-energy region than the Si K-edge, theDCM was equipped with pairs of crystals in
2014, Beryl (1010) and KTP (011). As a result,
XAFS measurements around 1keV such as
sodium, magnesium and aluminum became
possible. A comparison of the measured
magnesium K-edge XANES spectra by Beryl
crystal and KTP crystal is shown in Fig.1. The
sample was measured with the partial
fluorescence yield mode. If X-rays of a constantenergy are diffracted at the higher Bragg angle(in other words, the smaller the crystal latticespacing), higher energy resolution can beobtained. This effect can be confirmed from theby Beryl (10 10)

Normalized intensity（a.u.）

Introduction
X-ray absorption fine structure (XAFS)
spectroscopy has been used as a powerful tool
for analyzing the chemical state and thecharacterization of materials. Especially, XAFS
analysis in the soft X-ray region around 1 keV isimportant to industrial utilization because K
absorption edges of light elements such as
sodium, magnesium, aluminum can be analyzed.
BL05, beamline of NewSUBARU, wasconstructed on 2008 to respond needs for XAFS
of X-ray region arising from various industries[1, 2]. BL05A, a branch line of BL05, isequipped with a double crystal monochromator(DCM) that can provide the photon in the region
up to 4000 eV. XAFS measurements over the Kabsorption edge energy regions of silicon (morethan about 1800 eV) have been commonly
carried out by a crystal monochromator withInSb (111) crystal. In the lower-energy region
than the K absorption edges of silicon, Beryl and
KTP crystals are often used for XAFS
measurements. However, it is well known thatthese crystals are likely to be affected byradiation damage caused by synchrotron light. In
this paper, we report on the radiation damage ofthe KTP crystal of BL05A by synchrotron light.
1. XAFS measurements in the soft X-ray
region around 1keV
There are high demands on XAFS analysis in
the soft X-ray region 1 keV for industrial users.
Therefore, we have tried improvement of theberyllium filter in BL05A to improve the X-ray
transmission in the energy region. The filter isused to separate the ultra-high vacuum in thestorage ring with the front-end from the highvacuum in the beamline. We succeeded to makeby KTP (011)

1300

1320

1340

1360

Photon energy（eV）

Fig.1 Mg K-edge XANES spectra of
MgO powder.

27

1380

fact that the resolution of the spectrum gained by
KTP crystal is slightly higher than that gained by
Beryl crystal as shown in Fig.1.

vol.17, pp.16-17 (2015).
[5] T. Hasegawa et al., LASTI Annual Report,
vol.18, pp.37-38 (2016).

Current of reference electrode (pA)

2. Evaluation of the radiation damage of the
KTP crystal
Beryl crystals are often used for the XAFS
measurements of sodium and magnesium. On theother hand, KTP crystals are used for aluminum.
These crystals (in particular, KTP crystals) aresusceptible to damage caused by synchrotron
light. This may be attributed to their insufficientheat resistance. For the reason, high sensitive
XAFS measurements for these light elements are
generally very difficult in the synchrotron
radiation facility with the high energy
synchrotron light source. It is necessary to cool
the crystals in order to reduce the thermalloading of the crystals. Because thermal
expansion of crystals leads to a lattice strain in
crystals and a difference in lattice spacing
between first crystal and second crystal by X-ray
irradiation, which account for the degradation ofreflection efficiency of exit-beam. In BL05A, theplate equipped with the first crystals ismaintained at a precisely-controlled temperature
with accuracy of 22.0 +/- 0.1 degrees Celsius bya water-cooling system. In addition, thesecrystals are weakly adhered to a nickel coating
copper plate with gallium-indium (GaIn) alloys
to minimize thermal expansion. The transition of
intensity of diffracted light on KTP crystals isshown in Fig.2. We considered the current
measured by using an electrometer connected to
the reference electrode (Ni mesh) as the intensityof Bragg reflection. Despite the sufficientcooling of the first crystals, the decrease in thecurrent was observed. It is presumed that thedecrease was caused by radiation damage.
Furthermore, we measured the aluminum K-edge
spectra of -Al2O3 powder to investigate theeffect of the radiation damage on the energy
resolution of XAFS spectra (Fig.3). It is
confirmed that no degradation of the energy
resolution was observed in XAFS spectra while
the current of the reference electrode wasdecreased.

16.0
14.0 14.8
12.0

10.6

10.0

8.0

8.0

7.5

8.7

6.0

4.9

4.0
2.0
0.0

Date

Fig.2 Relationship between variation with timeand intensity of radiation light diffracted by
KTP crystal. (Incident X-ray energy: 1400 eV).
(a)A

7/22/2015
11/4/201512/16/2015
9/29/2016
6/2/2017

Intensity（a.u.）

B

1560

1570

(b)
Date

References[1] T. Hasegawa et al., Advances in X-ray Chem.
Anal. Jpn., 41, pp.99-106 (2010) [in Japanese].
[2] K. Kanda et al., J. Phys.: Conf. Ser., 425,
132005/1-4 (2013).
[3] T. Hasegawa et al., LASTI Annual Report,
vol.16, pp.73-74 (2014).
[4] T. Hasegawa et al., LASTI Annual Report,

1580

Photon energy （eV）

1590

FWHM (eV)A

B

7/22/2015

1.64

8.14

11/4/2015

1.65

8.07

12/16/2015

1.63

8.26

9/29/2016

1.63

8.14

6/2/2017

1.65

8.47

Fig.3 Al K-edge XANES spectra of -Al2O3
powder (a) and full width at half maximum(FWHM) as the photon energy resolution (b).

28Soft X-ray irradiation effect on the hydrogenatedSi containing DLC films
Kazuhiro Kanda1*, Shotaro Tanaka1, Ryo Imai1, Shuto Suzuki1, Takayuki Hasegawa1.2, Tsuneo Suzuki3,
Keiji Komatsu4, and Hidetoshi Saitoh4
1
Laboratory of Advanced Science and Technology for Industry, University of Hyogo, Kamigori, Hyogo, Japan
2
Synchrotron Analysis L. L. C., Kamigori, Hyogo, Japan
3
Extreme Energy-Density Research Institute, Nagaoka University of Technology, Nagaoka Niigata, Japan
4
Department of Materials Science and Technology, Nagaoka University of Technology, Nagaoka Niigata, Japan

Abstract

The effect of soft X-ray irradiation on hydrogenated silicon-containing diamond-like carbon(Si-DLC) films, which were expected to use as lubricant material in outer space, was investigatedusing synchrotron radiation (SR). We found that the volume of hydrogenated Si-DLC films
decreased by the SR exposure. This decrease in volume was attributable to desorption of hydrogen,and composition ratios of other elements hardly change by SR exposure. The local structure ofcarbon atoms in the hydrogenated Si-DLC film changed remarkably by SR exposure, on the other
hand, that of silicon atom hardly changed.

1. Introduction
Diamond like carbon (DLC) is amorphous
carbon film, and that has excellent properties, suchas high hardness, a low friction coefficient, highabrasion quality, a gas barrier, chemical inertness
and surface lubrication. Therefore DLC films are
utilized as many industrial fields, for instance,
automobile parts, hard disks, implant parts and foodcontainers.
Recently, utilization of DLC films as solid
lubricant for satellite is examined. Actuator ofsatellite is necessary to use lubricant, however, oilused in terrestrial cannot be used in outer spacebecause it freezes in vacuum. Thus, DLC films
expected to be used as lubrication instead of oil.
Especially, higher hydrogenated DLC (H-DLC)
films, which contain hydrogen more than 40 %,maintain low friction in vacuum, and are expected
for solid lubricant in outer space, where is known
for its unique hard environment, such as, soft X-ray,atomic oxygen and so on. Therefore, materials usedin outer space are required the durable against spaceenvironment. However, the degradation of H-DLC
film was reported to be caused by atomic oxygen
exposure. We found that H-DLC films, whichcontained Si atom, had the durability against theirradiation of atomic oxygen. Soft X-rays is anotherimportant environment in outer space. Therefore,clarification of the effect of soft X-ray exposure on
DLC films is important to ensure that DLC films areused in outer space safety.
In this study, modification of hydrogenated
Si-DLC films by the exposure to soft X-ray wasinvestigated. SR dose dependence on film volume
change, elements contents of surface and bulk,
integrated state of surface of C and Si, were
measured.

2. Experimental
Hydrogenated Si-DLC film was deposited on Si
wafer using an amplitude-modulated radiofrequency plasma-enhanced chemical vapour
deposition method (Nippon ITF Co.). This method
enables the deposition of DLC films containing a lotof hydrogen. Film thickness of as-depositedhydrogenated Si-DLC film was estimated to 522 nm
from observation of section image using a scanningelectron microscope (JEOL JSM-6700F).
The soft X-ray irradiation of hydrogenated
Si-DLC films was carried out at BL06. The SR was
irradiated onto the film surface perpendicularly. The
SR at the BL06 sample stage had a continuous
spectrum from the infrared to soft X-ray region lessthan 1 keV. This energy range includes 110 eV and
300 eV, which are the ionization energies of asilicon L shell and a carbon K shell, respectively.
During the experiment, the electron energy of the
NewSUBARU ring was 1.0 GeV and the ring
current was 300 mA in the top-up mode. The SR
dose [mA h] was derived as the product of the ring
current [mA] and the exposure time [h]. During theexposure of the hydrogenated Si-DLC films to soft
X-rays, the pressure in the irradiation chamber wason the order of 10-5 Pa and the temperature of thesample stage was confirmed to be room temperatureusing a thermocouple. After the SR exposure, themodified Si-DLC films were stored in a dry box.
3. Results and Discussion
To investigate the soft X-ray irradiation effect on
the hydrogenated Si-DLC films, we exposed such
films to synchrotron radiation (SR) in the soft X ray
region in the dose region from 0 to 2000 mA h andmeasured the degree to which the films’ properties
depended on the SR dose.

29

H/(H+Si+C) [%]Si/(H+Si+C) [%]3.1 Film thickness by stylus profiler and scanning films, using an electrostatic accelerator (Nisshin
High Voltage, NT-1700HS) located at Extreme
electron microscope
To estimate the degree to which hydrogenated Energy-Density Research Institute, Nagaoka
Si-DLC film thickness depended on the SR dose, University of Technology. He+ ion accelerated tothe hydrogenated Si-DLC films were exposed to SR 2.5 MeV using a tandem Pelletron accelerator were
through an Au mesh (wire diameter φ 0.07 mm, 100 used as the incident beam, whose angle with respect
mesh/inch) as a mask. The step depth was estimated to the surface normal was 72 degrees. At RBS
by using a stylus profiler (DEKTAK 6M) to experiments, recoiled He+ ion was detected by solidmeasure the difference in altitude between the area state detector (SSD), whose angle with respect toexposed to SR and a shadow area due to the Au the surface normal was 78 degrees. At ERDA
mesh. For the support to taking step depth experiments, hydrogen atom scattered by He+ ion
measurements, we observed section images of the was detected by another SSD, whose angle withhydrogenated Si-DLC film, which were a film as respect to the surface normal was 12 degrees.
Figure 2 shows the dose dependence of thedeposition and films after SR irradiation with SR
doses of 800 mA h and 2000 mA h, by using an hydrogen and silicon composition ratios inhydrogenated Si-DLC films. The atomic ratios of
SEM (JEOL JSM-6700F).
Figure 1 shows the degree to which the soft hydrogen and silicon were 0.4 and 0.2 before the
X-ray irradiation caused the film thickness to be SR irradiation and they were not changed after SR
dependent on the SR dose. The open and closed exposure. This result means that desorption of
circles respectively show the variation of film hydrogen in hydrogenated DLC was suppressed due
thicknesses estimated from measurements using to silicon doping.
SEM and a stylus profiler. Variation on film
50
50
thicknesses estimated from stylus profiler
measurements accorded well with those estimated40
40
from SEM measurements. The variation on
thicknesses increased gradually to about 60 nm after
30
30
2000-mA h SR exposure. At doses of more than
20
20
2000 mA h, the variation on thicknesses remained
constant at 70 nm. From these results, we confirmed
10
10Hydrogen content
that the hydrogenated Si-DLC film thicknesses
Silicon content
decreased due to soft X-ray irradiation, but that the
0
0
0
500
1000
1500
2000
increase was stopped at doses of 2000 mA h or more.
SR dose [mA·h]

thickness reduction [nm]100Fig. 2 Elemental composition ratio
dependence on hydrogenated Si-DLC film
bulk on SR dose, estimated by combining
ERDA and RBS. Circles and squares
respectively indicate hydrogen and siliconratios. Open circle and square indicatehydrogen and silicon ratios before the SR
irradiation.

80
60
40
20
0

0

1000
2000
SR Dose [mA·h]

3000

Fig. 1 Thickness reduction dependence ofhydrogenated Si-DLC film bulk on SR
dose. Open circles and closed circles were
estimated from SEM and profiler,
respectively.

3.2 Elemental composition in the hydrogenated
Si-DLC film obtained by combining of elastic
recoil detection analysis and Rutherford
backscattering spectrometry
We combined ERDA and RBS to estimate theelemental compositions of hydrogenated Si-DLC

3.3 Elemental composition and chemical state ofhydrogenated Si-DLC film surface by X-ray
photoelectron spectroscopy
We estimated elemental composition of thehydrogenated Si-DLC film surface by using a
conventional X-ray photoelectron spectroscopy(XPS) apparatus (Shimadzu, ESCA-1000). The Mg
Kα line (1253.6 eV) was used as the X-ray source
and incident angle was 45 degrees.
Figure 3 shows the dose dependence of theatomic composition of the hydrogenated Si-DLC
film surface. The circles, squares, and triangles
respectively show carbon, silicon and oxygen
contents. The carbon, silicon and oxygen contents in
the hydrogenated Si-DLC film surface before

30

irradiation were 0.4, 0.4 and 0.2, respectively.
The atomic composition of the hydrogenated
Si-DLC film surface was not changed after SR
exposure. On the other hand, it was necessary tonote that hydrogen content was not included in thisXPS result.

1500 mA·h

Carbon content
Silicon content
Oxygen content

1000 mA·h

Normalized Absorption [a.u.]

60
Elemental ratio [%]

SiO 2

50
40
30
20
10
0

0

500
1000
SR does [mA·h]

1500

Fig. 3 Elemental ratio of hydrogenated
Si-DLC film surface dependence on SR
dose with XPS. Circles, squares, andtriangles respectively show carbon, silicon
and oxygen contents. Open circle, square,
and triangle indicate carbon, silicon andoxygen contents before the SR irradiation.

800 mA·h

500 mA·h

200 mA·h

100 mA·h
80 mA·h

0 mA·h

1830

3.4 Local structure of carbon and silicon atoms
in the hydrogenated Si-DLC film obtained
through near-edge X-ray absorption finestructure measurements
NEXAFS spectroscopy using synchrotron
radiation is known to be sensitive to the local
structure around the absorber atom. To discuss onvariations in the local structure of the hydrogenated
Si-DLC film due to the exposure to SR, Si-K edge
NEXAFS spectra were measured. The NEXAFS
measurement of the Si K absorption was performed
at BL05A, which have a bending magnet as lightsource and a double crystal monochromator. The
NEXAFS spectra of the Si K edge absorption were
measured in the range 1810-1890 eV using
InSb(111). The energy resolution was estimated tobe less than 2.0 eV (FWHM). In the NEAXFS
measurement, irradiation angle irradiation angle tothe sample is the “magic angle” of 54.7° withrespect to the surface. The electrons coming fromthe sample were detected in total electron yield(TEY) mode. The intensity of the incident photon
beams (I0) was measured by monitoring thephotocurrent from a gold mesh. The absorption
signal was given by the ratio between theout-coming electron intensity from the sample, Is,
and I0.
Figure 4 shows the Si-K edge NEXAFS spectraof the hydrogenated Si-DLC film irradiated by SR,

1850
1870
Energy [eV]1890

Fig. 4 SR dose dependent Si K-edge
NEXAFS spectra of hydrogenated Si-DLC
films and those of some referencematerials.

of the film before irradiation, of some referential
materials, SiO2 powder, Si wafer, -SiC powder andamorphous hydrogenated silicon (a-Si:H) film. In
the spectra of Si wafer and a-Si:H film, the peaks
derived from SiO2 due to native oxidation wereobserved at 1846.8 eV. The Si atoms in thehydrogenated Si-DLC film can be expected to have
Si, C, H, and/or O as a neighboring atom. The
chemical environment around the absorbing atom
can be evaluated from the positions of theabsorption edge and the white line. The edge
position of Si K edge shifts to towards higher
energy with increasing positive charge on the Si
atom. The edge position of hydrogenated Si-DLC
film before irradiation was observed to 1840 eV,
which was located near those of Si wafer and a-Si:H
film. White line was observed at about 3 eV above
the absorption edge, which resembled those of Si
wafer and a-Si:H film. As a result, the chemical
environment of Si atom in the hydrogenated Si-DLC
film was close to those in the Si wafer and a-Si:H
film. After irradiation of SR, the peak of 1846.8
eV, which was derived from SiO2, was appeared at
the NEXAFS spectra of Si-DLC films. The intensity

31

HOPG
SiC powder

Normarized Absorption [a. u.]of this peak increased until 800 mA ･ h dose.
However, it decreased in the dose region more than
1000 mA･h dose. On the other hand, the intensity ofthe energy range about 1843-1846 eV increased.
This energy range derived from deoxidization of
SiO2. These results mean that SiO2 layer was
generated at the surface of hydrogenated Si-DLC
film by the oxidation of surface Si atoms withresidual oxygen in vacuum chamber due toirradiation of SR. The formed SiO2 layer was
deoxidized by the additional exposure to soft X-ray.
On the other hand, the positions of the absorption
edge and the white line did not varied by the SR
exposure. Therefore, the chemical environment of Si
atom in the hydrogenated Si-DLC film did notchanged by the irradiation of SR.
The C-K edge NEXAFS spectra of thehydrogenated Si-DLC film irradiated by SR havebeen reported in previous work (K. Kidena et.al.,Trans. Mat. Res. Soc. Japan, 40, (2015) 353-358).
Those were reshowed in Fig. 5, with those of of thefilm before irradiation, of -SiC powder and of acommercial DLC film as a typical DLC film. This
commercial DLC film was deposited on 200
nm-thick Si wafers using the ion plating method;
thus we call it IP-DLC film which consisted of only
carbon and hydrogen without silicon and otherhetero-elements. The hydrogen content of this
IP-DLC film was estimated to be 20% from a
combination of ERDA and RBS measurements. A
sharp π* peak observed at 285.38 eV is ascribed to
the C1s> π* resonance transition originating fromthe carbon-carbon double bonding. A broad σ* peakobserved at about 285-310 eV is ascribed to theC1s> σ* resonance transition. The C K-edge
NEXAFS spectra of Si-DLC films were classified asfour types with the silicon content. The C K-edge
NEXAFS spectra of hydrogenated Si-DLC films
before SR irradiation used in the present study wasclassified to type-3 reported in ref. RP130122.
That to say, the σ* peak was narrower than that oftypical DLC film and shifted to lower energy of 5eV, due to influence of peak of 289 eV derived
σ*(C-Si) peak. In addition, the peak intensity of* transition at 285.4 eV was weak. After1sirradiation of soft X-ray, the spectral features of C
K-edge NEXAFS spectra of hydrogenated Si-DLC*
film greatly varied. The peak intensity of 1stransition at 285.4 eV increased by the irradiation of
15 mA h of the SR dose. The σ* peak became
broader and shifted to higher energy. In other words,
the C K-edge NEXAFS spectra of hydrogenated
Si-DLC films concerted from type-3 to type-1 or 2.
As a result, the spectral features of hydrogenated

IP-DLC

1280 mA·h
640 mA·h
320 mA·h
40 mA·h
15 mA·h

Before irradiation

280

290
300
310
Energy [eV]Fig. 5 SR dose dependent C K-edge
NEXAFS spectra of hydrogenated Si-DLC
films and those of some referencematerials.

Si-DLC film after SR exposure of more than 320
mA･h resembled that of the typical DLC film,
which consisted of only carbon and hydrogen
without silicon. Therefore, C-Si bond decreased bysoft X-ray exposure at surface of hydrogenated
Si-DLC films.
4. Conclusion
SR dose dependences on several properties ofhydrogenated Si-DLC films were investigated. Filmvolume decreased with increasing of SR dose,
which was due to desorption of hydrogen, Chemical
states of carbon was changed by the SR exposure,but that of Si was not almost changed.

32

Refractive-index modifications in SiO2 Films
by Undurator Radiation with a multilayer spectrometer
1

K. Moriwaki1, S. Tanaka1, and K. Kanda2
Graduate School of Eng., Kobe Univ., 2LASTI, Univ. Hyogo

Abstract

Undurator radiation (UR) by the NewSUBARU (BL7A) is used for SiO2 modifications for futureapplications of optical devices like waveguides. UR with a multilayer spectrometer is used for the
samples irradiation. By a precise analysis, the refractive index is measured with a precision of lessthan 1x10-3. The resulted refractive indices indicate relatively flat dependence on the UR peak energy,
and show gradual increase by increasing the irradiation dose, especially in lower doses less than
500mAh. Defects generated in the SiO2 films by the UR irradiation are the most possible reason for
the refractive index increases. Optical absorbance increases by the defects in SiO2 films aremeasured, but correlation between it and the refractive index is not simple.

Introduction
Synchrotron radiation (SR) and undurator
radiation (UR) can be used especially forradiation-induced refractive index changes in
SiO2 film or bulk material for optical devices like
optical waveguides1,2). The former experiments
revealed differences between UR-irradiatedsamples with and without a spectrometer2). UR isa very useful tool for the materials modifications,because it can select a useful wavelength, andhave very high intensity. UR with a multilayer
spectrometer would be more useful for the
purpose because the most suitable wavelength
could be selected without higher order ones. In
this report, refractive-index modification effects
are investigated further than that in the previous
repots1,2). A new approach to obtain more precise
refractive index is also tried in the measurement.

Refractive index

1.47

1.465

1.46

1.455

1.45

1

2

3

4

5

6

7

8

9

10

Measurement number

Fig.1 Measurement error of Refractive index
in a same SiO2 film by reflection
spectrometry measurements. The arrowed
range means the precision of themeasurements.

Experiments and Results
Thermally grown SiO2 films (0.5m thickness)on Si substrates and fused quartz substrates wereused for the UR irradiation (BL-7A). UR with thefirst-peak energy ranging from 80 to 300eV isused with the spectrometer. Irradiated samples
werecharacterizedbyrefractive-index
measurements by a reflection spectrophotometry
and optical absorption spectroscopy.
Figure 1 shows refractive index changes
measured simply on a uniform surface of a SiO2
film 10 times. The results in Fig 1 means
measurement precision of 7x10-3 in the refractive
index values. As more precise values of therefractive index are needed in this study, wemeasured distribution of the refractive index n
and thickness d of the same SiO2 film on Si 100
times. Figure 2 shows that the product values ofmeasured n and d is very precise in spite of thevariation of the measured n in Fig.1. This isbecause optical measurements basicallydetermine the product of the n and the

800
700

nd (nm)

600
500
400
300

200
100
0

492

497

502

507

512

Thickness (nm)Fig.2 The product of the refractive-index n
and the thickness d as a function of d in a same
SiO2 film by 100-times reflection
spectrometry measurements.
propagation distance z of the electromagnetic
wave (nz is called optical path length), as thewave expression is cos(t-nz) where isangular frequency, t is time, and  is propagation
constant. By the results in Fig.2, n can be33

Absorbancedetermined more precisely (1x10-3 or less)utilizing the accurate value of thermally grown
SiO2-films thickness (500 nm). In the following
part of this report, n is determined by this analysis
scheme.
Very high refractive index changes after
irradiation by UR without the spectrometer wereintroduced in the samples that are mainly by thesurface reduction layer having Si-Si bonds2). By
using monochromatic irradiation with amultilayer film spectrometer, Si-Si bonds are notfound, so that the refractive index rises were notas high as those without the spectrometer2). In
this report, the photon peak-energy dependence
on the refractive index is shown in Fig.3. The
refractive indices in Fig.3 have no clear peak,though they might be relatively higher at aroundlower peak energies. The reproducibility in Fig3
is not enough at the present experiments. Further
experiments will by necessary because of theirimportance. On the other hand, the refractive
indices as a function of irradiation dose shows a

Refractive index

1.468
1.464
Reference

1.456
1.452
300

Refractive index

Fig.3 Refractive index changes at =633nm
in SiO2 films after irradiation by UR withthe spectrometer as a function of peakenergy.
1.476
1.474
1.472
1.470
1.468
1.466
1.464
1.462
1.460
1.458
1.456

100

200

300

400

500

0.12

ref

0.08
0.04
190 210 230 250 270 290 310 330 350 370 390
Wavelength (nm)Conclusions
SiO2 films were irradiated by UR with aspectrometer, and characterized for theirrefractive index changes. By fixing the SiO2 film
thickness, which is accurately determined as
500nm in the samples, the refractive index
change is more precisely analyzed at less than
1x10-3, comparing to the previous results. By
using the analysis, refractive index changes were
measured, as a function of irradiation dose or
photon peak energy. The mechanism to increase
the refractive index is not clear and the further
investigations are necessary. The authors thankR.Fujiwara for his help in the measurements.

Reference
0500mAhclear dependence on the dose as shown in Fig4.
In the previous experiments2), lower dose region
less than 500mAh were not characterized. By thedata in Fig.4, the refractive index is found to rise
gradually by increasing the irradiation dose.
Although the reason of the refractive index
increase by the irradiation is not clear enough,irradiation defects in SiO2 films would be themain part of the origin. Correlation between the
optical absorbance and the refractive index
changes was confirmed in the previous report2),
because defects increase the optical absorbance.
Additional results are obtained as shown in Fig.5.
By changing the irradiation dose, absorbanceincreases are also observed. However, thedependence on the dose is not simple as in a casein Fig.4. The mechanism to generate therefractive index increase may not so simple, andfurther investigation is necessary.

1.472

150
200
250
Peak Energy (eV)0.16

Fig.5 Optical absorbance for samples(dose of 500 and 1000 mAh) irradiated by
UR with the spectrometer. The peak
photon energy is 240 eV.

1.476

100

1000mAh

0

1.480

1.460

0.2

600

Dose (mAh)

References[1] K.Moriwaki et al., LASTI Annual Report 17,
55 (2015).
[2] K.Moriwaki et al., LASTI Annual Report 18,
43 (2016).

Fig.4 Refractive index changes at
=633nm in SiO2 films after irradiation
by UR with the spectrometer as a functionof dose.

34

P L2,3 Ultra-Soft X-ray Spectra of GaP and InP
Obtained without Energy Discrimination
Sei Fukushima1,3, Takanori Murano2, Hideyuki Takahashi2 and Kazuhiro Kanda1
1
3
LASTI, University of Hyogo, 2 JEOL Co., Ltd.,KMTL Co., Ltd.

Abstract

The CCD camera of the ultra-soft X-ray fluorescence spectrometer set on BL07A has no ability ofenergy discrimination. Thus, the overlapping of higher order lines cannot remove from themeasured spectrum so that the observed spectral change should be examined essential or not. In
this report, the spectral changes observed on P L2,3 of GaP and InP were studied using therelativistic cluster calculation.

Introduction
These past 4 years, new type ultra-soft
X-ray spectrometer has been developedand studied at the end point of BL07A. As
already shown in past Annual reports, thedetecting system used of ultra-soft X-rays
is a back-side illumination type SSD
camera for achieving high sensitivity andhigh detecting efficiency[1]. One the other
hand, this detecting system has no abilityof energy discrimination. Thus, thespectrum obtained this spectrometer iseasy to receive the interference of higher
order lines originated from another heavy
element in the sample. In the most casessuch as oxides or nitrides, the course of
the higher order lines can be estimatedeasily. An example of such cases, LiF, isshown in Fig.1[1], which spectrum wasmeasured by electron beam excitation. In
contrast, there are some cases that thecourse of the spectral changes cannot beeasily estimated that it is essential orinterference of the higher order lines. This
point is the serious problem for thechemical state analysis using the spectralchanges. One of the effective solution forthis problem is the storage of theexperience aided the theoretical study.
In this report, the spectral changes observedon P L2,3 of GaP and InP were studied. The
oxidation state and coordination state of P inboth compounds is exactly same. Whether it
could distinguish these two compounds from thechange of the spectrum was discussed using thecluster calculation.

Fig.1 Ultra-soft X-ray spectrum of LiF
with 10kV electron beam excitation[1].

Fig.2 P L2,3 ultra-soft X-ray spectra byelectron beam excitation. (a)GaP (b)InP
equipment of which composition of thespectrometer was almost same as that of BL07A.
The measurement was carried out by the
research laboratory of JEOL Co. Ltd.
As shown in Fig.2, the main peak of GaP
shifts lower energy side slightly from InP. And
the structure at the right side of main peak(above 120eV) is remarkably different eachother. Using the energy values of Ga L and L
by Bearden [2], the most of structures on P L2,3
of GaP can be assigned the higher order lines of

Measurement spectra
In Fig.2, P L2,3 ultra-soft X-ray spectra of
GaP and InP are shown. These spectra wereobtained with the electron beam excitation

35

Fig.3 The cluster model used in this study.
Ga L and L . However,there were no higher orderlines of In L series whichshowed agreement with thestructure on InP spectrum. In
addition, the energies of In
M series were not reported
anywhere. Thus, theoretical
calculation for obtain the
Fig.4
Electronenergy values of In M
transition diagram.
series of InP should benecessary.
As known well, the crystal structure of GaP
and InP is exactly same, and the only differenceis the lattice constant (GaP : 0.5466nm[3], InP :0.587nm[4]). Thus, if this spectral change above
120eV is caused by the difference of thebonding structure, study aided the cluster
calculation should be useful too.

Fig.5 Results of the cluster calculation(a) relativistic (b) non-relativistic
Results and Discussion
In Fig.5, theoretical P L2,3 spectra of GaP
and InP by relativistic and non-relativistic
calculation are shown individually. All the lines
were broadened with a Gaussian profile ofwhich FWHM was 1eV. In both calculation
results, the energy change of main P L2,3 peakshows same tendency. Thus, it can be clearlysaid that this small energy changes between GaP
and InP is essential so that one can distinguishthese two materials using this energy change.
As the result by the relativistic calculationshows clearly, the difference of the structure
below 120eV between both materials is hard to
be recognized. Because the each sub-shell of Ga
or In gives any effect to chemical bonding
individually, the relativistic calculation should
give more correct results than non-relativistic
calculation.
For making advance of discussion, theenergy calculation of Ga L 1,2, L 1 of GaP and
In M series of InP was carried out. According to
Barden’s data [2], the energy of Ga L 1,2 is1097.92eV and the splitting value between L 1and L 2 is negligible in 1st order. Thus, in thecase of overlapping on to P L2,3 line, thesplitting of L 1,2 is not necessary to consider.
The results of the relativistic calculation Ga
L 1,2, L 1 of GaP and In M series of InP are
shown in Fig.6. All the lines were broadenedwith a Gaussian profile of which FWHM was
10eV. 10eV width of 1st. order peak is about

Calculation
In Fig.3, the cluster model for both GaP and
InP is shown. The crystal structural data of bothcompounds were obtained from the database of
NIMS “Atom Work” (http://crystdb.nims.go.jp/
crystdb/search-materials) as CIF files. Both two
cluster models were PX4P12X12P6X12P24X163+(X=Ga or In) which were constructed within 7th
neighbor atoms from the center P atom.
The calculation method used in this study
was DV-X [5]. In the case of P L2,3, onlytransitions between 3d-2p (corresponding with
L 1,2, L 1) and 3s-2p (L , Ll) should be target
for calculation, because the energy splitting of
sub-shell (between LII and LIII, MIV and MV) aresufficiently narrow. However, in the cases of Ga
and In, the energy splitting of sub-shell are notdisregarding, as shown in Fig.4. Thus, in orderto calculate individual energies of thesetransitions, the relativistic calculation method isnecessary. The relativistic DV-X [6] was also
used for this aim, which was opened to public in
the limitation.

36

Fig.6 (a) Ga L 1,2, L 1 of GaP, and (b)In M
series of InP by the relativistic cluster
calculation.

Fig.7 The results of the superimpose
Fig.6 on Fig.5. (a) GaP (b) InP.

1eV width of 9th order, and 1eV is comparable
value of the energy resolution of thespectrometer used in this study. Barden’s data
[2] assigned M4,5-N2,3 transition to M in Sn
case, so that the strongest M4,5-N2,3 transitionline of In shown in Fig.6 was also assigned M .
Fig.7(a) shows the result thatsuperimposed 9th order Ga L 1,2 and L 1
calculated from Fig.6 on P L2,3 of GaP
shown in Fig.5(a). The intensity of 9thorder Ga lines were adequately adjusted
referring to the observation spectrum. As
shown in Fig.5(a), the structure above
120eV consists of two peaks of the almost
equal height. However, as shown in
Fig.2(a), the measured structure has two
different strength peaks, and thesynthesized spectrum shown in Fig.7(a) isvery similar to Fig.2(a). This result also
indicates this shape of structure reflects
the higher order Ga lines in GaP case.
Fig.7(b) was synthesized with Fig.5(a)and 3rd order In M series calculated from
Fig.6(b). It can be seen that the energy
position of 3rd order In M is almost samethe left side peak of the structure above
120eV. However, in Fig.2(b), the intensityof two small peaks is almost same, andthis is well corresponding with thecalculation result shown in Fig.5(a). Thus,in the case of InP, it can be concluded thatthe overlap of 3rd order In M is not
remarkable, and that the structure above
120eV shown in Fig.2(b) can be regarded
as the true structure.
Conclusion
In this report, the difference of P L2,3
spectra of GaP and InP was discussedwith the relativistic cluster calculation as
the example of examining the change ofultra-soft X-ray spectrum measured withthe detector which has not ability ofenergy discrimination. From the result of
calculation, it was found out that theenergy of the main peak of P L2,3 of GaP
was slightly lower than InP. And, about
the structure above 120eV on P L2,3, it wasalso found out that the shape of this of
GaP was almost same as InP, and that thehigher order (9th order) Ga L 1,2 wasremarkably overlapped this structure in
the case of GaP in spite for no observationof higher order lines of In M series on thatstructure of InP. In addition, it can be said
that the theoretical examination is so
useful for distinguish that the observed
spectral change is essential or not.
In spite of above discussion, thecauses of some of other spectral

37differences of P L2,3, the structure around100~110eV for example, could not be
revealed. It can be presumed that theorigin of this structure might not be thebonding structure of GaP or InP, and thatthe characteristic of the spectrometer
might be a cause of this structure.
References[1] S. Fukushima et al. Microchim. Acta 161,
pp.399 (2007).
[2] J. A. Bearden, Rev. Mod. Phys. 39, pp.78(1967)[3] R. Saravanan et al. J.Phys.Status Solidi B
165, pp.67 (1991).
[4] R. Saravanan et al. Z. Kristallogr. 200, pp.7
(1992).
[5] H.Adachi et al. J. Phys. Soc. Jpn. 45, pp.875(1978).
[6] H.Adachi, Technol. Rept. Osaka Univ. 27,
pp.569 (1977).

38

Growth of Monolayer Hexagonal Boron Nitride in Ultra-High
Vacuum for In-Situ Spectroscopic Analyses
Satoru Suzuki and Yuichi Haruyama,
LASTI, University of Hyogo

Abstract

We succeeded in growing atomically thin h-BN films in the endstation of BL7B. This enable us toanalyze the h-BN film by electron spectroscopic techniques using synchrotron radiation light withkeeping the sample in ultra-high vacuum.

Introduction
Hexagonal boron nitride (h-BN) is a
structural analogue of graphene and has alayeredstructure
consistingof
B3N3
six-membered rings. On the other hand, theelectronic structure of h-BN is complementary tothat of graphene. It is an insulator with a large
bandgap (about 6 eV), in good contrast to thatgraphene is metallic.
Recently,
many
applications of h-BN are expected, such as a
substrate material for graphene devices and an
atomically thin tunneling barrier. To study theelectronic structures of such a 2D material with
sub-nanometer-thick, soft x-ray spectroscopy isvery suitable, because interaction of soft x-ray
and a material is very large.
Now, the chemical vapor deposition (CVD)method is usually used to grow atomically thinh-BN. However, the CVD method often uses
toxic and flammable gases as a source andcarrier gas. Thus, safety is the concern. Moreover,
the CVD growth is usually done in relatively low
vacuum or even in atmospheric pressure.
Therefore, in-situ analyses of the growth byelectron spectroscopic technique is generally
very difficult.
We have proposed the diffusion and(a)precipitation method for growing atomicallythin h-BN [1-3]. This method only utilizes asolid source and solid state reaction. Thus, it ismuch more low-cost and safer than the CVD
method. Here, based on our previous studies[1-3], we report monolayer h-BN growth by the
diffusion and precipitation method in ultra-highvacuum. This enables us to analyze the h-BN
film by electron spectroscopic techniques usingsynchrotron radiation light with keeping thesample in ultra-high vacuum.
Experiments and Results
Figure 1 shows a schematic of the diffusionand precipitation method. A Ni foil with athickness of 25 m (Nilaco) was commerciallyavailable. As a B and N source, amorphous BN(a-BN) with a thickness of 100 nm wasdeposited on the Ni foil by using radio frequency
magnetron sputtering method [Fig. 1(a)]. Then,the sample was mounted in the sample
preparation chamber of the endstation of BL7B.
The a-BN-deposited side of the Ni foil was
irradiated by an electron beam and the sample
was heated at about 900-1000 C for typically 30
m [Fig. 1(b)]. At high temperatures, B and N

(b)

(c)

h-BN ( 1ML)(d)h

Ni foil

E
h-BN
Ni

a-BN
e

Fig.1 Schematic of monolayer h-BN growth by the diffusion and precipitation method. (a) a-BN
deposition on a Ni foil. (b) heating by electron bombardment in the endstation of BL7B. (c) h-BN
growth on the opposite face by diffusion and precipitation. (d) in-situ analysis using synchrotron
radiation light.

39

Intensity (arb. units)

atoms diffuse into Ni foil. The diffusion of B
atoms can simply be explained by the bulk
diffusion, because B is slightly soluble in Ni atsuch a high temperature [1]. The diffusion of N
atoms is very puzzling, because N solubility in
Ni is known to be almost zero even at hightemperatures [1]. We think that the masstransport of N atoms is caused by the grainboundary diffusion, although the details are still
open question. Anyway, atomically thin h-BN isultimately formed on the back side of the Ni foil
[Fig. 1(c)]. The sample was transferred from thesample preparation chamber to the analysis
chamber of the endstation of BL7B. Now, we
can analyze the h-BN film by photoemission
spectroscopy and x-ray absorption spectroscopy
with synchrotron radiation light [Fi.1(d)].
Figure 2 shows B-K absorption spectra of asample after the procedure shown in Fig. 1 andof bulk h-BN. The results unambiguously showthat h-BN is formed on the Ni foil. The large
incidence angle dependence indicates that theh-BN sheet is parallel to the surface of the Ni
foil, as reasonably expected. Currently, detailed
electronic structure of the monolayer h-BN on
the metal foil and the growth process of h-BN
are under investigation. Synchrotron radiation
photoemission
spectroscopy
and
x-ray
absorption spectroscopy will be powerful tools
to address these issues.

Fig.2 Polarized B-K absorption spectra ofmonolayer h-BN/Ni grown by the diffusion andprecipitation method and of bulk h-BN.
References[1] S. Suzuki et al., J. Phys. D: Appl. Phys. 45,
385304 (2012).
[2] S. Suzuki et al., J. Vac. Sci. Technol. B 31,
041804 (2013).
[3] S. Suzuki et al., Jpn. J. Appl. Phys. 56,
06GE06 (2017).

40

Evaluation on the molecular orientation in photoreactive
liquid crystalline polymer films by NEXAFS spectroscopy
1

Y. Haruyama1, M. Okada1, M. Kondo2, and N. Kawatsuki2
Laboratory of Advanced Science and Technology for Industry, University of Hyogo
2
Graduate School of Engineering, University of Hyogo

Abstract

The molecular orientation of the pre-aligned photoreactive liquid crystalline polymer PMCB10M
films has been investigated using the near-edge X-ray absorption fine structure (NEXAFS) at theC K-edge region. By combining the thickness dependence of PMCB10M films and three types ofsimultaneous detection methods of NEXAFS measurements, the molecular orientations of
PMCB10M films at the near-surface (<2 nm), at the inner-surface (~10 nm) and in the bulk (~100nm) were evaluated. In addition, it was found that the orientation of the liquid crystalline
molecules near the surface was parallel to the surface irrespective of the thickness of PMCB10M
films.

Introduction
The studies on the photoinduced molecularorientation of the polymeric films have attracted
significant attention for a potentially wide range
of applications such as birefringent opticaldevices, the photo alignment layer of liquid
crystal displays, and optical memories. The
polymethacrylatecomprisedof
4-methoxycinnamolybihenyl (MCB) side groups
connected via decylene spacers (PMCB10M) is
one of photoreactive liquid crystalline polymers[1, 2]. It was reported that the molecularorientation of photoreactive liquid crystalline
polymer controlled by the linearly polarized UV
radiation and the subsequent annealing
procedure [1, 2]. However, the molecularorientation of photoreactive liquid crystalline
polymer near the surface and the interface
between the film and the substrate is not clear.
To investigate the molecular orientation of
PMCB10M films, NEXAFS spectra at the C
K-edge region were measured by three types ofsimultaneous detection methods with thedifferent probing depth.
Experiments
PMCB10M was synthesized as described in aprevious paper [1]. PMCB10M films of 15-150
nm thickness were prepared by spin-coating atetrahydrofuran (THF) solution of the polymers
onto ITO coated glasses. The pre-aligned
PMCB10M films were prepared by irradiating
the linearly polarized UV light to the films andby subsequently annealing at 120-240 °C for 10
minutes.
NEXAFS experiments were performed at abeamline 7B of the NewSUBARU synchrotron
radiation (SR) facility, the University of Hyogo.
NEXAFS spectra were simultaneously measured
by Auger electron yield (AEY), total electron

yield (TEY) and fluorescence yield (FY)methods as shown in figure 1. The sample could
be rotated around a vertical axis to change theincidence angle of the SR to the sample surface.
The direction of the linear polarization in the SR
was horizontal. To evaluate the molecularorientation of PMCB10M films, NEXAFS
spectra were recorded in parallel andperpendicular configurations, where the directionof linearly polarized UV light irradiated to thefilms was parallel and perpendicular to that of
the linear polarization in the SR, respectively.
Results and discussion
Figures 2(a) and 2(b) show the C K-edge
NEXAFS spectra of pre-aligned PMCB10M
films, measured by the AEY method, as afunction of incidence angle of the SR in paralleland perpendicular configurations, respectively.
The thickness of PMCB10M films was 150 nm.
A sharp peak at 284.8 eV, which was assigned totransitions from the C 1s orbital to theunoccupied * orbitals originating from aromaticring sites, was observed [2, 3]. With increasing

Fig. 1 Three types of simultaneous detection
methods with the different probing depth [4].

41the incidence angle, the intensity of the peak at
284.8 eV decreased remarkably in the parallel
configuration while it was almost unchanged in
the perpendicular configuration. This indicatesthat the orientation of the liquid crystalline
molecules in PMCB10M at the near-surface isparallel to the polarization direction of the UV
light. On the other hand, the angular dependenceof the intensity at 284.8 eV in the TEY method
became smaller than that in the AEY method asshown in figure 2(c). In addition, the angulardependence of the intensity at 284.8 eV in the
FY method as shown in figure 2(e). had thesimilar angular dependence to that in the TEY.
These results indicate that the orientations of theliquid crystalline molecules in pre-aligned
PMCB10M films at the inner-surface and in thebulk are different from that at the near-surface.
NEXAFS spectra of pre-aligned PMCB10M
films in the thickness of 15 and 55 nm were alsomeasured in parallel and perpendicularconfigurations. In the case, the angulardependence of the intensity at 284.8 eV in the
AEY method showed the similar behaviour tothat in the thickness of 150 nm. Therefore, it was
found that the orientation of liquid crystalline
molecules near the surface was parallel to thesurface irrespective of the thickness of
PMCB10M films.

(a)

(b)

(c)

(d)

(e)

(f)

Fig. 2 C K-edge NEXAFS spectra of pre-aligned PMCB10M films, measured by the AEY, TEY, and FY
methods, as a function of incidence angle of the SR in parallel (a), (c), (e) and in perpendicular (b), (d),(f) configurations, respectively.
References[1] N. Kawatsuki and J. Horii, Mol. Cryst. Liq.
Cryst. 498, 49, (2009).
[2] N. Kawatsuki, Y. Taniguchi, M. Kondo, Y.
Haruyama, and S. Matsui, Macromolecules 48,
2203, (2015).

[3] N. Kawatsuki, Y. Inada, M. Kondo, Y.
Haruyama, and S. Matsui, Macromolecules 47,
2080, (2014).
[4] J. Stöhr, Nexafs Spectroscopy, (Springer
Series in Surface Sciences, 1996).

42

Analysis of Spray-pyrolysis Deposited NiOx Layers withDifferent Temperatures in Inverted Perovskite Solar Cells
Naoyuki Shibayama1, Hidetaka Sugita1, Yuya Nakazawa1, Hiroyuki Kanda1, Fukumoto Syota1,
Yuichi Haruyama2, and Seigo Ito1
1
Graduate School of Engineering, University of Hyogo
2
Laboratory of Advanced Science and Technology for Industry, University of Hyogo

Abstract

We investigated the effect of the NiOx layers on the performance of perovskite solar cells throughdetailed analysis (X-ray diffraction, X-ray and vacuum ultraviolet photoelectron spectroscopy) of
NiOx layers fabricated at different temperatures using spray pyrolysis deposition. It was confirmedthat the conversion efficiency of the perovskite solar cell is high as the crystallite size of NiOx islarge. It was also revealed that Na+ ions migrated from the glass substrate changed the band stateof the NiOx layer and affected the conversion efficiency. Based on the results of this study, it wasclarified that doping materials for hole and electron transport materials affect the band structure.
Engineering of these materials is important as a guide for improving the performance of perovskite
solar cells.

Introduction
The NiOx layer is actively used as holeextraction layer for inverted structure perovskite
solar cells. However, clear guidelines on NiOx
chemical composition, manufacturing methods,
energy levels, and the hole-transport process
remain unclear.
In this conference, high-density NiOx layerswith various manufacturing temperatures areproduced with Nickel acetylacetonate using the
SPD method in order to improve theperformances of inverted perovskite solar cells.
The chemical composition of the NiOx isinvestigated
using
X-ray
photoelectron
spectroscopy (XPS), and X-ray diffraction(XRD). Furthermore, the influence of Na+ ions in
the valence band of the NiOx layer isinvestigated by vacuum ultraviolet photoelectron
spectroscopy (PES) using synchrotron radiation.
The results showed that the conversion
efficiency of the perovskite solar cell is high as
the crystallite size of NiOx is large. The highest
perovskite solar cell conversion efficiency was
obtained at a NiOx layer production temperatureof 500 °C. Inversed perovskite solar cells were
fabricated with over 16.1% conversion efficiency

and no observed hysteresis. The conversion
efficiencies of the perovskite solar cells using
NiOx films with various deposition temperaturesare summarized in Table 1.
Experiments and Results
The perovskite solar cells conversion
efficiency increased along with the NiOx layer
production temperature to 550 and 600 °C;
however, it decreased slightly when thetemperature increased further to 600 °C. As aresult, the perovskite solar cell conversion
efficiency reached its peak when the NiOx layer
production temperature was 500 °C. To highlightthe performance change, we herein investigatedthe composition, structure and the band state of
the NiOx layers.
To investigate the states of the regions near
the edges of the valence bands of the NiOx
layers, PES measurements were carried out witha BL-07B end station at the NewSUBARU
synchrotron radiation facility at the University of
Hyogo, and the results are shown in Figure 1.
The regions near the edges of the valence bandsof the NiOx correspond to Ni 3d (label A), O 2p

Table 1. Parameters of photoelectric characteristics of perovskite solar cells.
NiOx fabrication
temperatures

Jsc(mA/cm2)

Voc
(V)

FF
(-)

η
(%)

300 °C

15.1

0.921

0.653

9.06

400 °C

17.6

0.966

0.657

11.2

500 °C

19.6

1.08

0.760

16.1

550 °C

18.2

1.01

0.706

12.9

600 °C

17.5

0.983

0.687

11.8

43

(label B), and the charge transfer transition from an
O 2p level to Ni 3d photoionization (label C). From
the PES measurement results, the region (around
4-5 eV) corresponding to O 2p was stronger at 300
and 600 °C than at 500 °C. This is because theinfluence of the O 2p orbital increased because theproportion of oxygen in NiOx increased owing to
the loss of Ni ions. Although the ratio of Ni2+ toNi3+ ions affects the energy levels in the vicinity of
the HOMO, a change in these energy levels does
not contribute to hole extraction in perovskite solar
cells. From these results, it was found that thevalence of the Ni ions has little influence on theperformance of the solar cells.

Intensity (a. u.)

600℃
Intensity (a.u.)C

600 °C, where the FTO layer broke beyond theglass transition point. In other words, as a guideline
for manufacturing high-performance inverted
perovskite solar cells, it is important to enlarge thecrystallites in the NiOx film.

A

B

550℃
500℃
400℃

600°C

300℃

500°C

35

45

55

65

75

85

2θ (degrees)

300°C
20

Fig. 2. Grazing-incidence X-ray diffraction patterns of
NiOx films for various SPD fabrication temperatures.

15

10

5

0

-5

Conclusions
We demonstrated that it is related to the NiOx
crystallite size and the conversion efficiency of theperovskite solar cells, which can be used as a
guideline to achieve high performance. The highest
perovskite solar cell conversion efficiency was
obtained at a NiOx layer production temperature of
500 °C. In the inverse perovskite solar cell, theconversion efficiency exceeded 16.1%, andhysteresis was not observed. Moreover, themeasurements of the valence band usingsynchrotron radiation indicated that the ratio of Ni2+
to Ni+3 had little effect on the solar cell
performance. This is an important guideline for
improving the performance of perovskite solar
cells.

Binding energy (eV)Fig. 1. Spectra obtained by PES using synchrotron
radiation in the valence-band region of the NiOx layer
as a function of the photon energy, taken at a photon
energy of 120 eV.

Both the structures and crystallite sizes of thethin NiOx films formed by SPD were investigated
via grazing-incidence X-ray diffraction (GIXRD),
as shown in Figure 2. The five peaks that appearedat 2θ values of approximately 37.6° 43.6°, 63.3°,
75.6°, and 79.6° were assigned to the 111, 200, 220,
311, and 222 planes, respectively, and thenattributed to the randomly oriented NiOx crystal. At
250 °C, no diffraction peaks were observed because
the NiOx film did not crystallise. This implies thatcrystallised NiOx films formed with annealing
temperatures above 300 °C.
The NiOx crystallite sizes were calculated fromthe intensities of the 200 peaks using the Scherrer
equation, and the results are shown in Figure 1,
which indicates that their sizes increased withincreasing SPD temperatures. The size of a NiOx
crystallite and the tendency of conversion
efficiency were consistent, except at 550 andReferences[1] A. Kojima, K. Teshima, Y. Shirai, T.
Miyasaka, Organometal Halide Perovskites as
Visible-Light Sensitizers for Photovoltaic Cells,
J. Am. Chem. Soc. 131, 6050 (2009).
[2] J. Nakazaki, H. Segawa, Evolution oforganometal halide solar cells, J. Photochem.
Photobiol. C. 2018, in press.

44

Cleaning of Carbon-Contaminated Ni-coated Mirror
Using Atomic Hydrogen
Masahito Niibe1, Tetsuo Harada1, Akira Heya2, Takeo Watanab1e, and Naoto Matsuo2.
1
LASTI, University of Hyogo, 2Graduate School of Eng., University of Hyogo

Abstract

In synchrotron radiation (SR) mirrors coated with easily-oxidized metal such as Ni or Cr, theUV-O3 ashing method cannot be used for removing the contaminated carbon film deposited during
use in the beamline. We have demonstrated that surface treatment technology using atomic
hydrogen is effective as a new contaminated carbon film removal technology. Hydrogen gas wasflew into contact with tungsten mesh (catalyst) heated to 1700 °C. to obtain atomic hydrogen. By
flowing this atomic hydrogen on the surface of the Ni-coatrd mirror, deposited contaminants could
be almost completely removed. The reflectance of the mirror recovered from about 10% to about
70% at the C-K absorption region. The reflectance also increased about 20% at the photon energy
greater than 300 eV because of the removal of carbon film and reduction of native oxide at themirror surface.

Introduction
Optical elements such as metal coated mirrors
installed in synchrotron radiation (SR) beamlines
are contaminated with mainly carbon consisting
film which is deposited during use, therefore thereflectance of the mirrors decreases. In many SR
facilities, efforts to deal with this problem havebeen done for a long time [1-3], but it has not yet
been completely solved. When the coating materialof the mirror is a noble metal such as Au, Pt, etc.,
ashing method using ozone gas under ultraviolet
irradiation (VU-O3 ashing) is used to remove thecontaminants [4]. However, when the coating
material is an easily-oxidizable metal such as Ni or
Cr, there is concern that the reflectance may belowered due to oxidation of the metal surface. As arecent previous study, Toyoshima succeeded inremoving contaminants in situ by introducing
oxygen gas into a mirror chamber at 8 × 10-2 Pa
and irradiating undulator light to a Cr-coatedmirror [5]. However, in order to realize such amechanism, it is necessary to install a large
differential pumping system, and oxidation of thecoating material has still been observed. Also,
Swaraj reported that contaminants were removed
and the reflectance recovered by keeping a small
amount of oxygen gas (~4 × 10-6 Pa) for 2 years inthe beam line during the time of beam operation[6]. However, this method takes time to recoverreflectance and the problem of surface oxidationfor easily-oxidizable metal is still unsolved.
We investigated carbon contamination removal
method of synchrotron radiation mirror bytreatment with atomic hydrogen (AH treatment).
There is a possibility that AH can preventoxidation even for a metal film which is easily
oxidized. We report the AH treatment on mirrors

which actually received carbon contamination
during the beamline operation and evaluate thereflectance of the mirror before and after thetreatment.
Experiments
The specimen is a Ni coated mirror on whichcontaminants are deposited, and which has beenused in the beam line, BL-09 [7], of the
NewSUBARU synchrotron radiation facility. For
cleaning of contaminants, atomic hydrogen
irradiation equipment of the University of Hyogo[8] was used. The W mesh was heated to 1700 °C,
and hydrogen gas was passed there at a gas
pressure of 30 Pa to obtain atomic hydrogen. The
distance between the W mesh and the treatedsample was 90 mm, and the heating operation of
the sample was not performed.
The evaluation of the mirror before and after the
AH treatment was carried out with visualobservation(photograph),surface
profilemeasurement by optical interferometer (Zygo,
NewView7300), surface roughness measurement
by atomic force microscope (AFM), thin film
structure in depth direction evaluation by hard
X-ray reflectometry at grazing incidence (XRR),
and surface composition analysis by X-ray
photoelectron spectroscopy (XPS, PHI 5000
VersaProbe). Because the size of the mirror is toolarge to introduce in the XPS chamber, we useddummy Ni coated mirror for XPS, which has
slightly contaminated with carbon film and has
been put together with the Ni-coated SR mirror
during the AH treatment.
The soft X-ray reflectance of the mirror before
and after this treatment was measured using a45

BL-10 reflectometer [9] of the NewSUBARU
facility. The measurement was carried out at a
grazing incident angle of 3°, and the reflectanceand its distribution at photon energy of 150 to 750
eV were evaluated.

50000
AH20170618
AHA 1700℃, 3600s
Ni/Cr/Si placed near Ni mirror
covered region

Intensity (counts)

40000

Results
First of all, as a preliminary experiment, thesurface roughness before and after the AHT was
measured and compared with a mirror coated with
Ni on the Si wafer substrate using atomic force
microscope. As a result, the surface roughness
hardly changed by this treatment.
The thickness of the contaminant on the Nicoated mirror was evaluated as 11 nm at the
maximum as measured by the optical interference
thickness gauge. The contaminants could be
removed by 1 hr atomic hydrogen irradiation tosuch a degree that trace was visible by visualinspection. Figure 1. shows the photographs of
Ni-coated mirror surface used in the beamline
BL-09 of the NewSUBARU SR facility (a) before,and (b) after the AH treatment. By the surface
profiler analysis, in this treatment, depositedcontaminants remained about 1 nm at maximum.

30000
20000

(a)

10000
0

1000

800
600
400
Binding energy (eV)

200

0

70000
AH20170618
AHA 1700℃, 3600s
Ni/Cr/Si placed near Ni mirror

Intensity (counts)

60000
50000
40000
30000
20000

(b)

10000
0

1000

800
600
400
Binding energy (eV)2000Fig 2. Composition analysis of the reference
mirror simultaneously introduced by XPS, (a)before, and (b) after the AH treatment.
Figure 3. shows soft X-ray reflectance spectrumof the Ni coated mirror in a wide photon energy
range from 150 to 750 eV before and after the AH
treatment. As shown in Fig. 3, even in the region
where the contaminants were thickly deposited, thereflectance could be recovered to about 10 70%.
It can be seen that the reflectance decreased toabout 50% due to accumulation of carbon
contamination even at an energy of 300 eV orhigher above the C-K absorption edge. With thisAH treatment, we could recover this reflectance toabout 70%, this value is close to the theoreticalreflectance.
At the photon energy of 280 eV or less, thereflectance is slightly decreased by the AH
treatment. This is because C, which isadvantageous in terms of optical constant at 280
eV or less, disappears from the surface, which istheoretically expected.
After this experiment, we also succeeded inremoving the contamination film by conducting
AH treatment on the Ni-coated diffraction grating(L150 × W30 × T20 mm, Si substrate) which also
received carbon film contamination.

(a)

(b)

Fig 1.
Photographs of Ni-coated mirror
surface used in the beamline of the
NewSUBARU SR facility (a) before, and (b)after the AH treatment
Figure 2. shows the composition analysis of thereference mirror simultaneously introduced by
XPS. Fig.2 showed that only the signal of C1s (280eV) decreased and the signal of Ni2p (850 eV)
increased and no special compound formation wasobserved.

As summary, we attempted a new cleaning46

method called atomic hydrogen treatment andcould successfully remove carbon contaminants
deposited on synchrotron radiation mirrors. The
damage (roughening or compound formation) of
the AH treatment to the mirror was very small.
This method is very simple and there is apossibility that contamination can be removed insitu without installing differential pumping systemor irradiation of intense undulator radiation.

References[1] K. Boller, R.-P.Haelbich, H. Hogrefe, W. Jark
and C. Kunz, Nuclear Instrum. Method. 208,273-279 (1883).
[2] T. Koide, S. Sato, T. Shidara, M. Niwano, M.
Yanagihara, A. Yamada, A. Fujimori, A. Mikuni,
H. Kato and T. Miyahara, Nuclear Instrum.
Method. Phys. Research A246, 215–218 (1986).
[3] R. A. Rosenberg, Nuclear Instrum. Method.
Phys. Research A291, 101–106 (1990).
[4] R. Kohli and K.L. Mittal Ed., Developments in
Surface Contamination and Cleaning (Elsevier,
Amsterdam, 2015), pp. 71–95.
[5] A. Toyoshima, T. Kikuchi, H. Tanaka, K. Mase,and K. Amemiya, J. Synchrotron Rad., 22,1359-1363 (2015).
[6] S. Swaraj, R. Belkhou, S. Stanescu, M. Rioult,A. Besson, and A. P. Hitchcock, J. Phys. Conf. Ser.
849, 012046 (2017).
[7] M. Niibe, M. Mukai, S. Miyamoto, Y. Shoji, S.
Hashimoto, A. Ando, T. Tanaka, M. Miyai, and H.
Kitamura, AIP Conf. Proc. 705, 576-579 (2004).
[8] A. Heya and N. Matsuo, Jpn. J. Appl. Phys. 46,
3545-3548 (2007).
[9] H. Iguchi, H. Hashimoto, M. Kuki, T. Harada,
T. Watanabe, and H. Kinoshita, Proc. SPIE 9658,
965819 (2015).

1

After AHT

Reflectance

0.8

0.6

0.4

Before AHT
0.2

0

200

300

400

500

600

700

Photon energy [eV]Fig 3.

Change in reflectance of Ni-coatedmirror before and after AHT.

47

Development of a standalone coherent EUV scatterometry
microscope with high-harmonic-generation EUV source for
EUV mask observation
Daiki Mamezaki, Tetsuo Harada, and Takeo Watanabe
Center for EUV lithography, LASTI, University of Hyogo

Abstract
We have developed a coherent EUV scatterometry microscope (CSM), which is a simple
microscope without objective optics. The EUV phase and intensity images were reconstructedwith diffraction images by ptychography. For a standalone mask review, thehigh-harmonic-generation (HHG) EUV source was employed. In this study, we updated thesample stage, pump-laser reduction system, and gas-pressure control system to reconstruct theimage. As a result, an 88 nm line-and-space pattern and a cross-line pattern werereconstructed. In addition, a particle defect of 2 m diameter was well reconstructed.
Introduction
Extreme-ultraviolet (EUV) lithography is themost promising method for manufacturing
semiconductor electronic devices. The EUV
mask is composed of an absorber pattern (50 70 nm thick) and a Mo/Si multilayer (280 nm
thick) on a glass substrate, which has athree-dimensional (3D) structure at the EUV
wavelength. The development of a review
apparatus for the EUV mask pattern at an
exposure wavelength of 13.5 nm is required. As
the 3D structure modulates the EUV reflection
phase, focus and pattern shifts are generated.[1]These phase modulations on the mask behave
similarly to an aberration. Thus, thedevelopment of the EUV microscope that canobserve both the intensity and phase images isstrongly required to control this aberration. For
EUV intensity and phase image observations,
we developed a coherent EUV scatterometry
microscope (CSM).[2,3] The CSM is a simple
microscope without objective optics developed
based on coherent diffraction imaging (CDI).[4]The EUV phase and intensity images arereconstructed with diffraction images, which are
diffracted from the mask pattern with coherent
EUV exposure. This coherent EUV illumination
is a key element for the CSM. In the previous
CSM system, a synchrotron radiation EUV light
was used as a coherent EUV source. The
synchrotron radiation is a large-scale facility,
which is not practical to use in a factory. For
practical uses, we have developed ahigh-harmonic generation (HHG) EUV sourceas the coherent EUV source of the CSM.[2] Thehigh harmonics, including the EUV wavelength
region, are pumped by a laboratory-scale
femtosecond laser.[5] The HHG source issuitable for CDI because of its high coherence.

Figure 1. Schematic
HHG-CSM system.

layoutoftheExperiments and Results
HHG EUV source
Figure 1 schematically depicts the HHG-CSM
system, which is composed of seven parts: (1) a
Ti:sapphire
femtosecond
laser,(2)alaser-focusing chamber, (3) a gas cell, (4) adifferential pumping chamber, (5) an EUV
branching chamber, (6) a spectrometer chamber,and (7) a CSM chamber. As the pump laser
system, we introduced the Spitfire Pro 6W(Spectra Physics), which is a commerciallyavailable table-top laser system. The main
specifications of the pump laser are wavelength:
800 nm, repetition frequency: 1 kHz, pulse
energy: 6 mJ, and pulse width: 36 fs. The
pump-laser light is led to the laser focusing
chamber. A thin MgF2 (1-mm-thick) crystal wasused as the vacuum window at the entrance of thelaser focusing chamber, which would not cause
the phase dispersion of the pump laser. The pumplaser was focused in the gas cell by asilver-coated concave mirror (radius of curvature:3 m) installed in the laser focusing chamber. The
focusing chamber and gas cell were filled withhelium gas with a pressure of 13.4 kPa. The
focused Ti:sapphire laser pumped the output of48

the high harmonics through a nonlinear
interaction with the helium gas. The 59th-orderharmonics of 13.5 nm wavelength (EUV light)
were used for the CSM system. The source of the
EUV light was determined to be 28 m indiameter on the basis of the full width at half
maximum (FWHM) criterion. High harmonics
were led to the CSM chamber by a branch mirror
with a Mo single-layer coating in the branching
chamber.
The HHG output included not only the EUV
light but also the pump laser. As the pump laser
power was 106 - 107 higher than the EUV output
power, the pump laser power should be reduced
to less than 1/10,000 of the EUV power. In thecase of residual pump laser power, the CCD
camera records the pump laser signal as the
background. Three Zr filters (200 nm thick) witha silicon-nitride back support (50 nm thick) wereinserted to reduce the pump laser power.
However, the filters were easily broken by thepump laser owing to its high power. To reduce
the pump laser power before the filters, a
reduction pinhole of 0.3 mm diameter wasinserted 600 mm downstream from the gas cell inthe differential pumping chamber. The beam
divergence of the pump laser (4 mrad) was morethan 10 times larger than the EUV output (0.2
mrad). The EUV beam almost passed through thepinhole; however, the transmitted pump laser
power was reduced to approximately 1/100. This
reduction pinhole was a simple mechanicalsystem with a high resistance to the pump laser
power. With this reduction pinhole, the Zr filters
were not broken by the pump laser power.

reflection and Zr filters. The diffraction from the
EUV mask was directly recorded by the CCD
camera. The diffraction image corresponded tothe amplitude information in the frequency space.
The focusing concave mirror had a radius ofcurvature of 350 mm and the distance between
the light source and the CSM concave mirror wasapproximately
3.0m.
Therefore,
themagnification of the CSM optics was 1/17. The
source of the EUV light was 28 m in diameter(FWHM). As a result, the expected focused beam
size on the mask was 1.6 m in diameter.

Figure 2. Schematic view of the CSM. The
diffraction image is the directory recordedwith the CCD camera.
EUV mask imaging method
The EUV mask pattern was reconstructed byptychography[6], which is a type of CDI. In
ptychography, the sample is illuminated withstep-and-repeat exposures. The diffraction
images are recorded at each step position. The
step length should be smaller than the beam
diameter to have an overlapped region. Thus,
some diffraction images have overlapped sample
information
under
different
illumination
conditions. This redundancy is an important
constraint condition in the iterative calculationsof ptychography. In this experiment, the scanningstep size was 0.8 μm, which was half the
expected focused-beam size. The sample was
illuminated in 15 × 15 steps, where theilluminated area was approximately a region of
12 × 12 m2. The diffraction images correspondto the amplitude information in the frequency
space. To reconstruct the real space image, phase
information was retrieved by the iterative
calculations of Fourier and inverse-Fourier

CSM system
Figure 2 schematically depicts our CSM. The
observation method is based on CDI, which is a
simple system without objective optics. The
CSM is composed of a concave mirror (radius ofcurvature: 350 mm) for focusing on the EUV
mask, a Mo/Si folding mirror, an EUV-maskstage, and an EUV CCD camera (Roper
Scientific MTE-2048B). The image size of the
CCD camera was 27.6 × 27.6 mm2. The distancefrom the mask surface to the CCD surface wasapproximately 109 mm. The HHG-CSM had anumerical aperture of 0.13. The expected spatial
resolution was a 54 nm half-pitch. The angle ofincidence in the mask was 6°, equal to that in the
EUV exposure tool. The EUV mask was exposedto the high harmonics, which weremonochromatized by the Mo/Si multilayer

49transforms with constraints. Therefore, thereconstructed image has amplitude and phase
information. The position accuracy and theillumination beam stability of the shape andintensity are very important in reconstructing themask pattern.
The output from the HHG gas cell included
high-power pump laser light. In previous systems,
the reduction pinhole was made of a SUS304
steel plate of 1 mm thickness. However, thepinhole melted owing to heating by thehigh-power pump laser beam. To improve thestability of the EUV light shape, a tungsten
pinhole with high thermal resistance was
employed. The thickness of this tungsten pinhole
was the same as that of the SUS304 pinhole (1mm thick). The melting point temperature oftungsten is 3,420 °C, which is 2.4 times higher
than that of SUS304 (1,400 °C). The beam shapewith this tungsten pinhole was significantly
improved; the beam had a clear round shapewithout any scattering light. The pinhole did not
melt after the half-year experiment using the
CSM.
Sample EUV mask
The EUV mask sample with an absorber line
pattern on the substrate. In this experiment, twotypes of absorber patterns were observed. One
was an 88 nm line-and-space (L/S) pattern,which was designed in a square region of 25 × 25
m2. Its line-to-space ratio was 1 to 1. This 88
nm L/S pattern corresponds to a 22 nm L/Spattern on a wafer. The other was a crossline-pattern of 2 m width and 10 μm length.

synchrotron bending light. In the diffraction
image of the 88 nm L/S pattern, the brightest
center part was the 0th-order light, which was a
specular reflection from the mask. The 1st-orderdiffractions were recorded near the 0th-order
light. Since the shape stability of the HHG EUV
source was improved by the tungsten reduction
pinhole, diffractions from the pattern wereclearly recorded.

Figure 3. Diffraction images from (a)cross-line and (b) 88 nm L/S patterns.

Figure 4. Reconstructed results of the corner
structure of the 88 nm L/S pattern in terms of (a)intensity and (b) phase contrast.
Reconstructed results of absorber patterns
Figure 4 shows a reconstructed image of acorner structure of the 88 nm L/S pattern. The
intensity image is shown in Fig. 4(a), and thephase image in Fig. 4(b). The line and corner
structures were well reconstructed. In the phase
image, the phase modulation of the line pattern
was observed. Thus, the CSM can observe theabsorber pattern phase, which is very importantin predicting the mask-induced aberration.
Figure 5 shows a reconstructed image of thecross-line pattern. The intensity image is shownin Fig. 5(a), and the phase image in Fig. 5(b). The
cross structure was well reconstructed. In theright part of the cross pattern, there were somereconstruction errors, because this region was at
the outer side of the step-and-repeat measurement.
In the phase image, we estimated the phase shiftof the absorber pattern. The cross-line region was
the reflective multilayer without the absorber.
The outside region of the cross structure wascovered with the absorber layer. The difference

Diffraction image using HHG-CSM
Figure 3 shows diffraction images from (a) across-line pattern and (b) an 88 nm L/S pattern
recorded by the CCD camera. The intensity isshown on a log scale. The measurement was
carried out at 15 × 15 points for step-and-repeat
measurements. The exposure time was 0.3 s ateach point. The readout time of the CCD camera
was 4.5 s per image. The total observation timewas 17 min at 15 × 15 points, where the readout
time was dominant for the observation time. The
EUV light intensity was 1.3 × 107 counts per s on
the CCD camera. The exposure dose on the mask
was estimated to be 71 pW. The power density inthe focused beam was approximately 3.5
mW/cm2. This EUV power of the HHG-CSM
was 175 times higher than that with the50

[6] J. M. Rodenburg and H. M. L. Faulkner, Appl.
Phys. Lett. 85, 4795 (2004).

between the absorber and reflective regions wasestimated to be 2.8 rad (160°). The CSM canestimate the absorber phase shift, which is very
important for the attenuated phase-shift mask. In
addition to the cross pattern, the natural defectthat seems to be a particle on the pattern wasobserved. The phase shift of the particle was thesame as the absorber pattern, which indicatedthat this particle would be a peeled absorber. The
phase shift was very helpful in characterizing thedefect origin.

Figure 5. Reconstructed results of the cross-line
pattern in terms of (a) intensity and (b) phase
contrast.
The HHG-CSM clearly showed the 88 nm L/Sand cross line patterns on the EUV mask. In
addition, a natural defect that seems to be apeeled-absorber particle on the cross line waswell reconstructed. A high spatial resolution of
54 nm half-pitch was expected in this CSM withan NA of 0.13 equivalents. This result shows the
successful observation of the EUV mask patternusing the HHG-CSM. The CSM also showed the
EUV reflection phase modulation, which causes
the mask aberration and degrades the wafer
image. Thus, the CSM will be a powerful system
for EUV phase review in factories, such as mask
shops and semiconductor fabrication plants.
Acknowledgement
The HHG EUV source was developed by Yutaka
Nagata of RIKEN.
References[1] T. Last, L. de Winter, and J. Finders, Proc.
SPIE 9635, 96350K (2016).
[2] M. Nakasuji, A. Tokimasa, T. Harada, Y.
Nagata, T. Watanabe, K. Midorikawa, and H.
Kinoshita, Jpn. J. Appl. Phys. 51, 06FB09 (2012).
[3] Y. Tanaka, T. Harada, T. Amano, Y. Usui, T.
Watanabe, and H. Kinoshita, Jpn. J. Appl. Phys. 53,
06JC03 (2014).
[4] J. Miao, D. Sayre, and H. N. Chapman, J. Opt.
Soc. Am. A 15, 1662 (1998).
[5] Y. Nagata, T. Harada, M. Nakasuji, H.
Kinoshita, and K. Midorikawa, Proc. SPIE 8849,
884914 (2013).

51

Evaluation of Block Copolymer Structure
Using Soft X-Ray Scattering (BL-10)
Yusuke Nakatani, Tetsuo Harada, Motoyuki Yamada, and Takeo Watanabe
Center for EUV lithography, LASTI, University of Hyogo

Abstract

We developed a scattering measurement method using soft X-rays near the carbon absorption edge.
Since the absorption spectrum varies in the near carbon absorption edge for each polymer
molecule, the individual physical structures can be observed from the scattering profile withdifferent photon energy. In this study, both the physical and chemical structures of the triblock
terpolymers such as poly(isoprene-block-styrene-block-(2-vinylpyridine)) which consists ofpolyisoprene, polystyrene, and poly(2-vinylpyridine) were observed. By varying the photon energyof the scattering measurement, the scattering light intensity changed greatly, and the signal fromeach polymer could be evaluated. The soft X-ray scattering measurement at the near absorption
edge can be measured the molecular structure of a composite material such as a blended polymer
individually and can be utilized in material development.

Introduction
The directed-self-assembly (DSA) is one of thecandidates for the advanced lithography of half
pitch (hp) 5 nm and below to fabricate
semiconductor devices.
In general, the X-ray absorption spectroscopy(XAS) is very powerful tool to evaluate theelectronic state of each element of the chemicalcompound. We have developed this method forcharacterizing extreme-ultraviolet (EUV) resist
materials at NewSUBARU BL-10 beamline [1].
Under EUV exposure, from the absorption peakvalue and the chemical shift in the X-ray
absorption spectra, the chemical bonding changes
can be estimated at the CK region. As the result, it
can be understood the EUV chemical reaction foradvanced EUV resist materials by XAS
measurement. Recently, evaluation of stochastic
process in resist such as acid diffusion and its
distribution, and distribution of functional groups
become significant issue to achieve low
line-edge-roughness. Thus, it is required toevaluate the chemical state and functional groups
distribution in nanometer scale. If the spatial
resolution of XAS realize in nanometer scale, thestochastic which is own to the electron state ofeach element in the resist material can be
captured by this high-spatial-resolution XAS.
The scattering measurement is benefit for
observation of the physical structure. In X-ray
region, small angle X-ray scattering (SAXS) is
widely used for the physical structure analysis
using the X-ray energy of 8 keV in usual.
In this study, soft X-ray scattering employed asa probe light with varied photon energy was
employed to study the physical and chemical

structures of a tri-block polymer. The scattering
signal from the sample includes not only the
information of the physical structure but also theinformation of the chemical structure. And thescattering signal intensity depends on thechemical state near the absorption edge. Wang etal. reported this scattering method of resonant
soft X-ray scattering (RSoXS) for themeasurement of the triblock terpolymers such aspoly(1,4-isoprene-block-styrene-block-(2-vinylp
yridine)). The RSoXS is used for themeasurement of spatial composition correlations
in organic sample [2].
In this study, we have analyzed the physicalstructure of poly(isoprene-block-styrene-block(2-vinylpyridine)) (ISP) triblock terpolymer
blends. In this paper, isoprene, styrene, and2-vinylpyridine polymers are represented as I, S,
and P polymers, respectively. This terpolymer has
cylinder structure of I and P polymers in S
polymer. These samples were also measured by
the transmission electron microscopy (TEM).
The block copolymer consists of two or morecovalently bonded polymer chains andself-assembles by microphase separation into aregular microstructure [3]. The 3-component
block terpolymer is widely used for controllingmorphology with a complicated microphaseseparated structure [4].
Experiments and Results
samplesFigure 1 shows the triblock polymer samples
with (a) hexagonal packed cylinders and (b)tetragonal packed cylinders, respectively. Thesesample were prepared by same method for the52physical structure observation using TEM. The
triblock polymer was packed by surrounding
with epoxy resin. Thin packed sample weresliced to a thickness of 400 nm using a
microtome. The ultrathin sections were floatedon a water and transferred onto a Cu grid withhaving a center hole of 1.5-mm-diameter.
(a)Fig. 2. Schematic diagram of the scattering
measurement system which is installed in the BL-10
beamline.

Fig. 2 shows a schematic diagram of thescattering measurement system which is installedat the BL-10 beamline. A 100- m pinhole wasused as an aperture for the soft-X-ray incident
beam. The distance from the pinhole to thesample is 30 mm, and the distance from thesample to the CCD camera is 33 mm. The
maximum acceptance angle is 24°, whichcorresponded to qmax of 0.59 nm-1 at 280 eV.
The scattering light from the sample isrecorded by the CCD camera in vacuum. To cut
off the direct light with strong intensity, a
1-mm-wide center-stop plate was set in front of
the CCD camera.
The scattering angle and pitch of the sample
structure are described by the following
diffraction equation eq. (1).

(b)

Fig. 1. Photograph of the optical-microscope sample
images of ISP triblock copolymers; (a) the hexagonal
packed copolymer, and (b) the tetragonal packed
copolymer.

=

RSoXS method
In this study, we have constructed a RSoXS
measurement system at the BL-10 beamline of
the NewSUBARU synchrotron light facility. The
BL-10 beamline has a bending magnet as a lightsource, and a monochromator which is a
Monk-Gillieson type spectrometer using
varied-line-spacing grating with incident slitlessdesign to monochromate the incident photon
energy. The photon energy range to expose on asample is from 60 to 1100 eV. The number ofphotons estimated by photodiode current at the
focal point under the condition of the exit-slit 20
m is 4 × 109 photons/s at the photon energy of
280 eV. The energy resolution E/ΔE isapproximately 2500. The scattering measurement
chamber using in this study is installed at 2.1 m
downstream from the vertical and horizontal
focal points in the beamline. The stage and the
CCD camera which we have been used for a
EUV microscope described in the paper [5].

(1)Where d is the pitch of the cylinder structure, θ isthe scattering angle, m is the diffraction order,and λ is the wavelength of the incident soft X-ray.
Hexagonal packed cylinder
Figures 3(a)-(e) show scattering images of thehexagonal packed ISP triblock terpolymer at five
photon energies of 280.0, 284.0, 285.6, 288.6,
and 300.0 eV, respectively. And in each figure,the contour plots of the light intensity distribution
is shown in logarithmic scale.
Figure 3(f) shows a TEM image of thisterpolymer. The black circle, the grey circle, andthe back white region indicate the I, P, and S
polymers, respectively.
In the scattering images, the bright centerregion indicates scattering light from the incident
pinhole. The outer region of this scattered light
was blocked with the Cu grid hole. The black53

rectangle at the center region indicates shadow of
the center block plate, which blocked the bright
direct beam.
Two scattering signals with the ring-shapewere recorded, with ellipse shape, not circle
shape. The radius of horizontal direction was
smaller than the vertical direction. This ellipse
indicates that the sample is stretched along thehorizontal direction. In addition, the ring-shapeindicates that the domain size of the terpolymer
is sufficiently smaller than the beam diameter of
100 m. This scatter signal is an averaged signal
obtained from a small cylinder having a random
direction.

estimated to be 49 nm along the horizontal
direction, and 39 nm along the vertical direction.
The inner ring had 3 times larger pitches. The
d-spacing ratio and TEM image indicates that theouter and inner rings corresponded to thescattering from the P-P and I-P physicalstructures, and I-I physical structure. These
structures are shown in Fig. 3(f).

Fig. 4. TEY result around CK region of three polymers
which were coated on Si wafers individually.

Figure 4 shows XAS result of the threepolymers coated on Si wafers measured by the
total electron yield (TEY) method at the BL-10
beamline described in the paper [7]. The TEY
signal depends on the absorption of its sample,
where the large TEY signal indicates large
absorption. The three polymers which were
included in the terpolymers were the I, S, and P
polymers. At the photon energy of 280.0 eV, theabsorption of all three polymers were small andapproximately same. At the photo energy of
284.4 eV, the absorption of the I and S polymers
were approximately same, and the P polymer had
slightly small absorption. As a result, only the
inner scattering ring of the nearest neighborscattering was observed as shown in Fig. 3(b). At
the photon energy of 285.6 eV which canassigned as * bonding of benzyl group, threepolymers had large and different absorption. As aresult, both the outer and inner scattering rings
were observed. At the photo energy of 288.6 eV,
the S and P polymers had approximately sameabsorption. As a result, only the inner scatteringring was observed, which corresponded toscattering from the I-I physical structure.
Since scattering efficiency depends on not only
the absorption but also the refractive index, it ishard to discuss the scattering signal only with the
TEY result. However, the refractive index isFig. 3. Scattering and TEM images of the hexagonal
packed ISP triblock terpolymer.

The scattering intensity of scattered ringstrongly depends on the incident photon energy.
The outer ring signals were observed as shown in
Fig. 3 (a), (b), and (c), the inner signals wereobserved as shown in Fig. 3 (c), and (d). At theabsorption energy of 285.6 eV which canassigned as * bonding of benzyl group, thescattering intensity of the two rings werestrongest. The d-spacing of the outer ring was54

3(a)-(e) around q = 0.093 nm-1 and 0.16 nm-1,
where these d-spacing of its physical structure
width were 68 and 39 nm, respectively The ratioof these peaks is exactly 3. The scattering
intensity strongly depends on the photon energy.
The scattering intensity ratio of the outer peak to
the inner peak was also changed with varying thephoton energy. For example, at the photon energyof 285.6 eV, the ratio was approximately 1,
where the scattering signals were due to the P-P,
I-P, and I-I polymer physical structures. At thephoton energy of 288.6 eV, the scattering signal
was mainly due to the I-I polymer physicalstructures because the intensity ratio was 0.4. The
scattering contrast of the P polymer to the base S
polymer was small. At the photon energies of
280.0 and 284.0 eV, the ratio was 6. The
scattering signal was due to the P-P polymer
physical structure. The scattering contrast of the Ipolymers to the base S polymer was very small.
Thus, the RSoXS measurement resolved the I
and the P polymer physical structures.

close related to the absorption, and the scattering
intensity was strongly depended on theabsorption. At the RSoXS measurement, it ispossibletoobtainscattering
signals
distinguishing the polymer types by changing theprobe photon energy.
This triblock polymer usually measured by the
SAXS. However, the scattering signal includes
only the I polymer physical structure in the S andP polymers. For the SAXS measurement, thephoton energy is usually 8 keV. The S and P
polymer has the same contrast. Thus, it is hard toachieve the P polymer physical structure
information.
Figure 5 shows the scattering profiles of thehexagonal packed cylinders observed by sevenphoton energy conditions. The horizontal axis
shows the scattering vector (q), which is shownin Eq. (2).

=

( )

(2)

Tetragonal packed cylinder
Figures 6(a)-(e) show the scattering image ofthe tetragonal packed ISP triblock terpolymer. In
each figure, the contour plots of the lightintensity distribution is shown in logarithmic
scale. Figure 6(f) shows the TEM image. Figure
7 shows the scattering profiles of the tetragonal
packed cylinders observed by seven photon
energy conditions.
In the scattering image of Figs. 6(a)-(e), there
was no ring-shaped scattering like the hexagonal
packed cylinders. Four scattering signals wererecorded at each inner and outer region. This
non-ring scattering indicates the domain size of
this terpolymer was larger than the illumination
size of 100 μm. The azimuth angle of the inner
scatterings has 45°-difference from that of theouter scatterings. The scattering angle of theouter scatterings was approximately 2 times
larger than that of the inner scatterings. The
d-spacing of the inner scatterings was estimatedto be 59 nm. The d-spacing of the outerscatterings was estimated to be 42 nm, whichcorresponded to that of the I-I and P-P physicalstructures.
Since the scattering angle ratio of thehorizontal
toverticaldirections
wasapproximately one, this terpolymer was notstretched. The scattering intensities of the innerfour scatterings were symmetric, and asymmetric

The vertical axis shows the scattering intensity
at the radial position. Since it is an ellipse rather
than a circle, scattering intensity in verticaldirection is shown in Fig. 5.

Fig. 5. Radial intensity average obtained by thescattering measurement results of the hexagonal
packed ISP triblock terpolymer.

As results, at the seven photon energy from250.0 eV to 300.0 eV in Fig. 5, there are two
peaks of inner and outer ring as shown in Fig.

55

and I-P structures at the photon energies of 280.0
and 284.0 eV. The outer asymmetric scattering
signal was due to nearest neighbor the P-P
physical structure shown in Fig. 6(f). As a result,microdomain structure of the P polymer would
have the lamellar structure, which caused thisasymmetric scattering. This structure was notobserved in the TEM image.
In the RSoXS, soft X-rays irradiates on a thinfilm sample, and a scattering signal
corresponding to the structure of the sample
material and the absorption / refractive index
contrast is obtained. By changing the energy ofincident light near the absorption edge, thecontrast images of the constituent atoms,
molecular structure, and chemical state can beobtained. Therefore, it is possible to distinguisheach component of blend polymer having closedensity, and it is a method that can evaluate thestructure of each molecule. Especially, it ispossible to obtain very strong intensity withrepetitive pattern and it is suitable for physicalstructure analysis of the triblock terpolymer.
Acknowledgement
The author would like to thank Dr. Atsushi
Takano for providing the triblock terpolymer
samples.

Fig. 6. Scattering and TEM images of the tetragonal
packed ISP triblock copolymer.

References[1] K. Emura, T. Watanabe, M. Yamaguchi, H.
Tanino, T. Fukui, D. Shiono, Y. Haruyama, Y.
Muramatsu, K. Ohmori, K. Sato, T. Harada, andH. Kinoshita, J. Photopolym. Sci. Technol., 27,
631 (2014).
[2] C. Wang, D. H. Lee, A. Hexemer, M. I. Kim,
W. Zhao, H. Hasegawa, H. Ade, and T. P. Russell,Nano Lett., 11, 3906 (2011).
[3] F. S. Bates, G. H. Fredrickson, Phys. Today,
52, 32 (1999).
[4] Y. Asai, A. Takano, and Y. Matsushita,
Macromolecules, 49, 6940 (2016).
[5] T. Harada, Y. Tanaka, T. Watanabe, Hiroo
Kinoshita, Y. Usui, and T. Amano, J. Vac. Sci.
Technol. B, 31(6) , 06F605-1 (2013).

Fig. 7. Radial intensity average obtained by thescattering measurement results of the tetragonal
packed ISP triblock terpolymer.

at the outer side. According to the previous
hexagonal packed case, the P-P physical structure
was observed without the information of the I-I

56

Total-electron-yield measurements of insulating thick film
samples put on conductive substrates
Yasuji Muramatsu and Yukina Tani
Graduate School of Engineering, University of Hyogo
Abstract
We have proposed a new method for soft X-ray absorption measurements of insulating thickfilms using a total-electron-yield (TEY) method. TEY of insulating paper, cloth, and tapesamples put on conductive substrate can be successfully measured in BL10/NewSUBARU.
This method enables to easily measure TEY-XANES of insulating film samples whose
thickness is several-tens μm.
1. Introduction
The yield of electrons emitted from matterby X-ray irradiation is generally proportional to
the X-ray absorption intensity. Thus,
photocurrent can flow in electrically conductive
matter by X-ray irradiation when matter isgrounded. The photocurrent measured ingrounded matter is usually called as sample
current. Monitoring the sample current during
the X-ray energy scanning is easy using X-ray
absorption spectroscopy (XAS), which is a total
electron yield (TEY) method [1,2]. In particular,
the TEY method is commonly used in soft X-ray
absorption
spectroscopy
becausethefundamental transmission method for XAS isdifficult to apply to soft X-ray absorption
measurements.
Although numerous XAS studies haveused the TEY method to examine electricallyconductive materials, it is generally hard to
apply the TEY method to insulating bulk
materials because sample charge-ups distort the
TEY. To avoid or suppress charge-up effects ofinsulating bulk samples during X-ray irradiation,bulk samples are often powdered and placed on
conductive substrates [3, 4]. The TEY of theinsulating powder samples can be easily
measured via the sample surface in contact witha conducting substrate. This system effectively
monitors the surface sample current of
insulating
particles,butitrequiresdeconstructive preparations of bulk samples. We
have quite recently found another method toeasily observe the TEY of insulating bulk thinsamples [5]. In this method, insulating thinsamples are put on conductive substrates, andthe sample current generated by soft X-ray
irradiation can be efficiently detected though thebackside of the substrate. Such phenomena
suggest that electrically conductive paths are
induced inside insulating thin samples by soft
X-ray irradiation. This paper demonstrates the

TEY measurements of insulating thick films
such as papers, clothes, and tapes which are puton conductive substrates [6].
2. Experiments
Figure 1 shows insulating thick film
samples of papers, wiping clothes, and tapes,
which are put on a conductive carbon tapesubstrate. Label, thickness, and density of thesamples are denoted in the Figure. Thickness ofthese samples are approximately 40 ~ 150 μm.
Papers take middle density of 0.46 ~ 0.82 g/cm3,
wiping clothes take lower density of 0.20 ~ 0.23
g/cm3, and tapes take higher density of 1.0 ~ 1.3
g/cm3. Sample current of these film samples
were measured through the carbon tapesubstrate during soft X-ray irradiation. Sample
current and TEY measurements were performed
in BL10/NewSUBARU. Spectral measurements
in 200 - 600 eV, CK, and OK regions.

Fig. 1 Insulating film samples of paper, wiping
cloth, and tape, which are put on a conductive
carbon tape substrate.
3. Results and Discussion
3.1 TEY-Spectra of Thick Film Samples
Figure 2 shows sample current and TEY
spectra in the 200 – 600 eV region of the57

samples. Sample current of paper and tapesamples is several pA, and that of cloth samples
is several tens pA. It is therefore confirmed thatsample current of these thick film samples canbe surely measured through the carbon tapesubstrate. TEY-XAS of them exhibits CK and
OK absorption structures. This clearly showsthat XAS of such the insulating thick films canbe easily obtained with the TEY method.
Absorption intensity in the CK region of paper
and tape samples is fairly smaller than that in
OK region. On the other hand, CK intensity islarger than OK intensity in wiping cloth samples.
These results imply that the measured sample
current is strongly dependent on the excitationenergy and density of the samples. In paper andtape samples, the lower CK intensity than OK
intensity results in the lower energy and higher
density. In the wiping cloth samples, the higher
CK intensity results in lower density.

exhibits different profiles in paper, wiping clothand tape samples. The OK-XANES of them arealso clearly observed. It is therefore confirmedthat chemical analysis of the insulating thickfilms can be performed with the TEY method. It
is additionally mentioned that the 2nd order of
OK absorption is little observed in the lower
energy region of CK-XANES. This means that
2nd order diffraction can be effectively
suppressed in BL10/NewSUBARU, which is anadvantage for the CK-XANES analysis by using
this TEY method.
3.2 Application for Environmental Samples
XANES of environmental dust samples
collected on filter papers were directly measured
for demonstration of the TEY method. Upper panelof Figure 4 shows a photo of samples. Air
monitoring PTFE filter membrane and dust
collected on the filter were put on a conductive
carbon tape substrate. Lower panel of Figure 4
shows the sample current spectra of the samples.
The samples exhibit several pA in the 200 – 600 eV
region. Absorption peaks in CK, NK and OK
regions are clearly observed in the sample.

Fig. 2 Sample current (a) and TEY-XAS in the
200 - 600 eV region of the paper, wiping clothand tape samples.

Fig. 4 Upper panel (a) shows a photo of the filterand dust on filter samples put on conductive carbon
tape. Lower (b) shows sample current spectra of thefilter and dust on filter samples.
Figure 5 shows the XAS or XANES in the
200 - 600 eV, OK and CK regions of the dust on
filter and filter samples, and the spectral
difference of (dust on filter) - (filter). The spectral
difference in the 200 – 600 eV region clearlyshows the CK, NK, and OK absorption peaks ofdust. The spectral difference in OK region exhibits

Fig. 3 XANES in the CK (a) and OK (b) regionsof the paper, wiping cloth and tape samples.
Figure 3 shows XANES in the CK and
OK regions of the samples. The CK-XANES

58

the π* peak at 530 eV, suggesting the carbonyl
oxygen on dust surface. The spectral difference in
CK region exhibits a small π* peak at 285.5 eV
and an intense peak at 288 eV. This suggests thatthe dust contains small portion of aromatic or
unsaturated organic compounds and thatoxygenated organic compounds are clearly exist
on dust surface. It is therefore confirmed that
XANES of environmental samples collected on
insulating filters can be directly observed by using
the proposed TEY method.

4. Conclusion
XANES of insulating thick film samples of
paper, wiping cloth, and tape can be successfullymeasured by using the TEY method in which theinsulating samples are put on conductive substrates.
For application of the present method,
TEY-XANES of environmental dust samples
collected on filters can be measured. It is therefore
concluded that the proposed TEY method will be a
powerful tool for chemical analysis of insulating
thick film samples.
References[1] J. Stöhr, C. Noguera, and T. Kendelewiez, Phys.
Rev., B30, 5571-5579 (1984).
[2]
J.
Stöhr,
NEXAFS
Spectroscopy(Springer-Verlag, 1996) pp. 118-133.
[3] G. J. Baker, G. N. Greaves, M. Surman, M.
Oversluisen, Nucl. Instrum. Meth. in Phys. Res.,
B97, 375-382 (1995).
[4] H. M. Wang and G. S. Henderson, J. Non-Cryst.
Solids, 354, 863-872 (2008).
[5] Y. Muramatsu, The76th Annual Meeting ofAnalytical Chemistry, Japan, F1010 (2016).
[6] Y. Muramatsu, Y. Tani, Y. Tobita, S. Hamanaka,and E. M. Gullikson, Adv. X-Ray Chem. Anal.
Japan, 49, 219-230 (2018).

Fig. 5 TEY-XAS in the 200 - 600 eV region (a),and TEY-XANES in the OK (b) and CK (c)regions of the filter and dust on filter samples.
Subtracted spectra of (Dust on filter) - (Filter) arealso described in the figures.

59Chemical analysis of coal tar using soft X-ray absorption
spectroscopy
Yasuji Muramatsu and Kosuke Shirai
Graduate School of Engineering, University of Hyogo
Abstract
To characterize coal tar, we have measured XANES in CK, NK, and OK regions of them in
BL10/NewSUBARU. Minor components of nitrogen and oxygen can be successfully detected
and chemical states of them were estimated with a finger print method. The π* peak map fromCK-XANES suggested that the coal tar samples can be identified from the size of aromaticcompounds as major components.
can be detected by TEY-XAS.

1. Introduction
Coal tar is one of the important industrial
carbon materials. It is well known that coal tar
takes complex structure of aromatic andaliphatic compounds. The compounds have been
usually analyzed chromatographic method,
infrared (IR) spectroscopy, and NMR [1].
However, local structure of coal tar has not beenclearly clarified by using these conventional
analytical methods. In this study, we havemeasured XANES of various industrial coal tar
samples to identify the local structure of them.
2. Experiments
Commercially available six coal tar
samples (denoted as T1 ~ T6) were used forcharacterization of coal tar. Coal tar is generally
sticky liquid and electrically insulating. Thus,
we have prepared thin coal tar samples on gold(Au) substrates; (1) coal tar was dissolved inorganic solvent, (2) the solution was dropped ona gold (Au) substrate, and (3) evaporate thesolvent.
X-ray absorption spectra (XAS) of tar
samples were measured at the XAS system [2-5]in BL10/NewSUBARU, and partially measured
in BL-6.3.2/ALS (Advanced Light Source).
XANES in the CK, NK, and OK regions were
measured with a total-electron-yield (TEY)method. For finger print analysis for NK- and
OK-XANES, reference aromatic compounds
having nitrogen and oxygen functional groups
were also measured [6,7].

Fig. 1 TEY-XAS in the 200 - 600 eV region oftar samples.
Figure 2 shows the CK-XANES. Each tar
exhibits π* peak at 285.5 eV and σ* peak at 293
eV. Such the profiles suggest that major carbon
components of tar are aromatic compounds.
Characteristic peaks are also observed at287~289 eV, which suggests the aliphatic C-Cstructure. Thus, components of tar can be
estimated to be aromatic compounds as major
components with aliphatic compounds.
As shown in Figure 1, N is a minor
portion in tar. However, N is surely incorporated
as shown in NK-XANES of Figure 3. The
NK-XANES exhibit three peaks (denoted as a ~c). From the finger-print analysis compared toreference N-having aromatic compounds, thepeaks a ~ c suggest the structures of -NH2 and N
in aromatic rings.

3. Results and Discussion
3.1 XANES
Figure 1 shows XAS in 200 - 600 eV
region of tar samples (T1 ~ T6). Each sample
can be successfully measured with a TEY
method without charge up. All samples exhibit
intense absorption at CK edge and weakabsorption at NK and OK edges. It is therefore
confirmed that small portions of N and O in tar

60

Fig. 2 CK-XANES of tar samples.

Fig. 4 OK-XANES of tar samples.
3.2 Identification of Tar on π* Peak Map
Width and height of π* peak in CK-XANESof graphitic carbons are strongly dependent on local
structure of hexagonal carbon layers [8]. From thetheoretical analysis of π* peak profile in various
aromatic compounds and graphitic particles, wehave clarified that the relationship between thewidth and height of π* peak are determined by theedge structure and size of hexagonal carbon
structures. Then, we have proposed a unique index"π* peak map" for identification of graphitic carbon
structure from the relationship [9].
We have applied the π* peak map to the tar
samples. Figure 5 shows the CK-XANES of tar
with reference HOPG (highly oriented pyrolytic
graphite). Subtracted spectra of (Tar) - (HOPG) arealso described on XANES. A peak at 284 eV(denoted as a) in the subtracted spectra means thewide portion of π* peak of tar compared to HOPG.
Thus, peak a height is an index for π* peak width.
The π* peak map can be plotted with the π*/σ*peak height ratio as the function of peak a height.
Figure 6 shows the π* peak map of tar samples with
the nano-graphite [9] and carbon black. Comparing
to the nano-graphite and carbon black, tar samples
distributed upper area on them. This suggests thatmajor carbon compounds are polycyclic aromatichydrocarbons (PAH) in which edge carbon atoms
may be more than 50% in all carbon atoms. In tar
samples, π* peak height widely distributes in 1.0 ~1.5. This also suggests that molecular size of the
PAH components distributes in T1~T6.

Fig. 3 NK-XANES of tar samples.
Figure 4 shows OK-XANES. All tar samples
exhibit three peaks (denoted as d ~ f). From thefinger-print analysis compared to referenceO-having aromatic compounds, the peaks d ~ fsuggest the structures of carbonyl or quinone >C=O
and -OH.

61

References[1] Z. Sun and W. Zhang, Chin. J. Chem. Eng., 25,
815-820 (2017).
[2] Y. Muramatsu, A. Tsueda, T. Harada, and H.
Kinoshita, Adv. X-ray Chem. Anal., Japan, 43,
407-414 (2012).
[3] Y. Muramatsu, A. Tsueda, T. Uemura, T.
Harada, and H. Kinoshita, Adv. X-ray Chem. Anal.,
Japan, 44, 243-251 (2013).
[4] T. Uemura, Y. Muramatsu, K. Nambu, T. Harada,and H. Kinoshita, Adv. X-ray Chem. Anal., Japan,
45, 269-278 (2014).
[5] T. Uemura, Y. Muramatsu, K. Nambu, D.
Fukuyama, M. Kuki, T. Harada, T. Watanabe, and H.
Kinoshita, Adv. X-ray Chem. Anal., Japan, 46,
317-325 (2015).
[6] Y. Muramatsu, S. Ueda, and E. M. Gullikson,
TANSO, 236, 9-14 (2008).
[7] T. Amano, K. Shirode, Y. Muramatsu, and E. M.
Gullikson, Jpn. J. Appl. Phys., 52 041304 (2013).
[8] Y. Muramatsu, T. Ooe, T. Okada, and E. M.
Gullikson, Proceedings of the 9th International
Symposium on Atomic Level Characterizations for
New Materials and Devices ’13, ALC'13, 516-518(2013).
[9] Y. Muramatsu, K. Murayama, and T. Okada,
Proceedings of the 10th International Symposium
on Atomic Level Characterizations for New
Materials and Devices ’15, ALC'15, 27p-P-38(2015).

Fig. 5 CK-XANES and subtracted spectra between
tar and HOPG.

Fig. 6 π* peak map of tar samples compared tonano-graphite and carbon black.
4. ConclusionWe
have
successfullymeasuredTEY-XANES in CK, NK, and OK regions of tar.
Minor portion of N and O can be clearly observed.
From the finger print analysis using referencecompounds, chemical state of N and O in tar can be
estimated. From the π* peak map, major
components of tar are confirmed to be PAH in
which edge carbon atoms may be more than 50% in
all carbon atoms. It is therefore concluded that
XANES is a powerful tool for characterization of
tar.

62

Sample holder for TEY-XAS measurements in BL10 ofextended rubber samples
Yasuji Muramatsu and Yuki Tobita
Graduate School of Engineering, University of Hyogo
Abstract
A new sample holder of the extended rubber has been developed for X-ray absorption
measurements in BL10/NewSUBARU. By using the holder, CK XANES of extended
isoprene rubber (IR) and carbon black (CB) -mixed IR samples were successfully measured.
The sample holder enables XANES analysis of rubber from the view point of conformation ofrubber polymers.
On this holder, extended rubber sheets can be
fixed on side plates with screws. Width of themeasuring area on rubber is 13 mm. Threerubber samples can be put on the holder. The
sample holder can be rotated around verticalaxis as shown in right panel of the Figure.
Direction of extension is parallel to thepolarization of incident soft X-ray beam. Thus,
incident-angle-dependent
XANES
measurements can be performed to investigate
the orientation of the rubber molecules.

1. Introduction
Property of rubber is strongly dependent
on local structures and interactions among thecomponent compounds such as rubber polymers,
carbon black, sulfur, and oxygen. Oxygen isespecially an important component for
degradation of rubber. However, the component
molecules take complex structures and thestructure is dependent on extension. To clarify
the local structure of rubber by using XANES in
BL10/NewSUBARU, we have developed asample holder for extended rubber. This reportbriefly describe the holder and XANES oftypical rubbers measured by varying theextension.

3. XANES of the Extended Rubber Samples
To demonstrate the utility of the holder,
XANES of the extended rubber samples were
measured in BL10. Rubber samples are typicalisoprene rubber (IR) and carbon-black mixed IR(CB-IR), which were supplied from Yokohama
Rubber Co., Ltd. Thin sheet samples of IR and
CB-IR were extended on the holder with theextension of x1, x2, and x3. Incident angle (θ)
was also varied to 90 (normal incidence), 54.5
(magic angle) and 30 degrees. XANES in the
CK region can be measured with a total electron
yield (TEY) method by monitoring sample
current through the holder and transfer plate.
Figure2shows
theincident-angle-dependent CK-XANES of theextended IR and CB-IR samples. IR and CB-IR
samples exhibit the π* peak at 285.5 eV, σ*peak near 293 eV, and peaks at 287 - 289 eV.
The π* peak reflect unsaturated bonds in IR
molecules. The peaks at 287 - 289 eV suggest
the saturated C-C bonds. In both IR and CB-IR,
π* peak height depends on extension. Thissuggests that conformation of unsaturated bonds
can be changed by extension. Figure 3 showsthe π* peak height as the function of extension.
The π* peak height of IR decreases as theextension increases. However, behavior of theπ* peak height of CB-IR is different from IR.
This suggests that conformation and local
structure of unsaturated bonds in IR polymers

2. Details of the Holder
X-ray absorption analysis system in BL10[1-4] uses a sample transfer plate with the sizeof 75mmL x 25 mmW. Thus, the sample holder
for rubber should be put on the transfer plate.
Left panel of Figure 1 shows the developed
rubber holder which fits to the transfer plate.
Size of the holder is 75mmL x 25 mmW x 8mmT.
The holder is made from aluminum.

Fig. 1 Left photo shows the newly developed
sample holder for extended rubber samples.
Right shows the schematic of the holder forincident-angle rotation.

63

are strongly dependent on CB particles.

mentioned in Figure 3, π* peak height depends on
extension in both IR and CB-IR. However, the π*
peak height is not dependent on incident angle. Thismeans that unsaturated bonds in extended rubber
are not oriented in the sample plane.

Fig. 4 The π* peak heights of the extended IR and
CB-IR as the function of cos2θ.
4. Conclusion
Sample holder for extended rubber samples
were developed and XANES measurements of theextended rubbers can be successfully demonstrated.
By using the holder, XANES analysis of the rubber
can be performed by varying extension and incident
angles in BL10.

Fig. 2 Incident-angle-dependent CK-XANES of theextended IR and CB-IR.

References[1] Y. Muramatsu, A. Tsueda, T. Harada, and H.
Kinoshita, Adv. X-ray Chem. Anal., Japan, 43,
407-414 (2012).
[2] Y. Muramatsu, A. Tsueda, T. Uemura, T.
Harada, and H. Kinoshita, Adv. X-ray Chem. Anal.,
Japan, 44, 243-251 (2013).
[3] T. Uemura, Y. Muramatsu, K. Nambu, T. Harada,and H. Kinoshita, Adv. X-ray Chem. Anal., Japan,
45, 269-278 (2014).
[4] T. Uemura, Y. Muramatsu, K. Nambu, D.
Fukuyama, M. Kuki, T. Harada, T. Watanabe, and H.
Kinoshita, Adv. X-ray Chem. Anal., Japan, 46,
317-325 (2015).

Fig. 3 Extension-dependent π* peak heights of IR
and CB-IR.
Figure 4 shows the π* peak heights of the extended
IR and CB-IR as the function of cos2θ. As

64

Deterioration Analyses of Polymer Thin Film
Hideo Kobayashi1, Yosuke Azuma1, Yasuko Mitsushita1, Shogo Suehiro1,
Sohta Hamanaka2, Keigo Yoshida2, Yuki Tobita2, and Yasuji Muramatsu2
1

Sumika Chemical Analysis Service, Ltd.,
1-135, Kasugade-Naka 3-chome, Konohana-ku, Osaka 554-0022, Japan
2
Graduate School of Engineering, University of Hyogo,
2167, Shosha, Himeji, Hyogo 671-2280 Japan

Abstract
Usage environments affect the surface of polymers used in automobiles, home appliances, andother products. We conducted the deterioration analyses of polyamide and polybutylene
terephthalate films by using soft X-ray absorption spectroscopy at BL10/NewSUBARU. In
this report, we discuss the changes in the molecular structure and molecular orientation of thesurface of these polymers due to heat deterioration.
Introduction
Polymers are widely used in many products,
such as automobile, home appliances. As forautomobile, many of the parts, such as interior andexterior decors are made from polymers. These
polymers continue to deteriorate from the surface
by UV and heat.
Soft X-ray is useful for surface analysis andtotal electron yield (TEY) method makes it
possible to analyze insulating samples. We havestudied about materials used for organic
light-emitting diodes so far. However, polymers
are difficult to analyze due to their poor electricalconductivity and complex structures.
The purpose of this study is to analyze polymer
deterioration by using soft X-ray absorption
spectroscopy (XAS) with TEY method at
BL10/NewSUBARU.

TEY. To examine the molecular orientation, theincident angles of soft X-ray were tuned to 90°,54.5°, and 30°.

Normalized intensity / a.u.

Results and Discussion
1. Deterioration analysis of polyamide usingchemical bonding state
Figure 1 shows X-ray absorption near-edge
structure (XANES) for CK-edge of untreated PA
and heated PA. These spectra clearly show thatthe peak positions were different around 293 eV.
From CK-XANES, spectral analysis with DV-Xα,
this difference is considered to be the result of
cutting and random recombination of CO-NH bondby heating. XAS is an effective measure tosurface deterioration, since detection depth of XAS
is nano-order.

Experiments
1. Deterioration analysis of polyamide usingchemical bonding state
Polyamide (PA) was cut to 1.5 μm thickness by
microtome. In order to examine deterioration
caused by heating treatment, heat-treated PA film
at 140°C over 50 hours and untreated film were
measured by XAS. XAS measures were performed
across carbon K-edge, nitrogen K-edge and oxygen
K-edge (CK, NK and OK) with TEY. The
incident angle (θ) of soft X-ray was tuned to 90°.

Untreated PA
Heated PA
10

2. Deterioration analysis of polybutylene
terephthalate using molecular orientation
Polybutylene terephthalate (PBT) was cut to
1.5 μm thickness by microtome. In order toexamine deterioration caused by heating treatment,
heat-treated PBT film at 180°C over 6 hours anduntreated film were measured by XAS. XAS
measures were performed across CK and OK with

280

290
300
Photon energy / eV

310

Figure 1. CK-XANES spectra of heated PA anduntreated PA.
The difference of peak
positions around 293 eV is considered to be theresult of cutting and random recombination of
CO-NH bond by heating.

65Normalized intensity / a.u.

2. Deterioration analysis of polybutylene
terephthalate film using molecular orientation
No difference in XANES was observed
between untreated PBT and heated PBT measured
at θ = 54.5°.
Figure 2 shows the θ-dependent CK-XANES of
PBT samples. The spectra were taken at incident
angles of 30° ~ 90°, which were normalized by σ*peaks at 294 eV. PBT samples exhibit strong
θ-dependence of the π* peak intensity at 285 eV,
exhibiting minimum at θ = 30°, and maximum at θ
= 90°. This tendency indicates that π bond ishorizontally-oriented.
To estimate orientation angles, normalized
intensities of π* peak were plotted in Figure 3.
The angle (α) between the perpendicular π* orbitalto the substrate surface and the molecular plane
was calculated according to the method of previous
study[1]. The calculation gave α = 48° for untreated
PBT and α = 41° for heated PBT. It is speculated
that this change of α was caused by rearrangementof PBT with annealing.
Untreated PBT

θ =

π*

Iv(θ) / Iv(θ = 90°)

3

290
300
Photon energy / eV

2
1.5
1
0

30

60

90

Incident Angle / degree

Figure 3. Molecular orientations of untreated
PBT and heated PBT. Plots are experimental
data and curve lines are calculated data [1].
Reference[1] F. Zheng, B. N. Park, S. Seo, P. G. Evans, F. J.
Himpsel, J. Chem. Phys., 126, 154702 (2007).

30°
54.5°
90°

σ*

280

2.5

0.5

1

0

Untreated PBTHeated PBT

310

Figure 2. Incident angle dependency of
XANES for untreated PBT. These spectra
were normalized by σ* peak at 294 eV. The
tendency of π* peak intensity indicates that theorientation of π bond is horizontal to PBT
surface.

66

Crystallographic orientation of graphite along activatedsurface of iron particle via mechanochemical process
Satoshi Motozuka1, Keigo Yoshida2, Sota Hamanaka2 and Yasuji Muramatsu2
1

Department of Mechanical Engineering, Gifu National Colledge of Technology, Gifu, Japan
2
Graduate School of Engineering, University of Hyogo, Himeji, Japan

Abstract
This study aims to examine crystallite orientation of graphite particles along mechanochemically preparedsurfaces on iron particles using angle-dependent C K-edge X-ray absorption near edge structure (XANES)
spectroscopy at the BL10 beamline of the NewSUBARU synchrotron radiation facility. Two types of ironsurfaces, bare iron and iron oxide, were mechanochemically prepared on iron particle surfaces using aball-milling process under ambient atmosphere and Ar-3%H2 atmosphere, respectively. During milling, ironparticles were plastically deformed and their shape changed from granular to platelet. Simultaneously,
milled graphite particles adhered onto the platelet surface of the iron particles. The angle-dependent
XANES spectra revealed that the mechanochemically prepared surfaces affect the orientation of the basal
plane of the graphite particle adhering to them.
would be formed on the iron particles milled ineach atmosphere during milling.
XANES measurements were conducted atbeamline BL10 of the NewSUBARU facility at
the University of Hyogo. XANES spectra at theC K-edge region were collected via the total
electron yield method to investigate the crystal
orientation of graphite on the milled ironparticles. The milled samples were embedded in
indium plates using a spatula. As shown in
Figure 1, the milled samples were gradually
deformed and their shape changed from granular
to platelet during milling. Therefore, when theparticles were pressed against the indium plateby the spatula, the platelet particles
spontaneously oriented with their surface
parallel to the indium plate surface. The indium
plate samples could be rotated around a verticalaxis to change the angle of incidence of the SR
to the sample surface.

Introduction
Mechanochemical surface treatment is a
powerful tool to modify a solid state and to
introduce new defect states that are unachievable byother means [1]. Since the defective structure is an
unstable or metastable state, the structure willinteract with surrounding materials. In this study,bare iron and iron oxide surfaces with defectstructures were achieved via mechanochemical
processing using a ball-milling method. The
configuration interaction between the surfaces andgraphite particles present in the milling vessel as amechanochemical reactor were investigated using
X-ray absorption near edge structure (XANES)
measurements at the BL10 beamline of the
NewSUBARU synchrotron radiation facility.
Experimental
Water-atomized iron particles (ML35N,
Kobe Steel Co., Ltd., D50 = 125.0 μm, purity>99.8%) and graphite powder (UCP,
Nihonkokuenkogyo Co., Ltd., average diameter:ca. 10 m, purity >99%) were processed usingball-milling. The iron (5 g) and graphite (0.035g) particles were placed in a stainless steel
vessel, and 20 steel balls were added as themilling medium. The vessel was mounted on acentrifugal ball mill and swung at 59.1 rad/s for1.0 h. The vessel was surrounded by a water
jacket to suppress the heat generated by milling.
Milling was conducted under ambient
atmosphere, and another mixture of iron andgraphite particles were milled under an
atmosphere.
AlthoughtheAr-3%H2
measurement system used in this work cannot
confirm due to air exposure before themeasurement, bare iron and iron oxide surface

Fig. 1 Representative SEM images of ironparticles milled for 0, 0.10, 0.50, and 1.00 h
under ambient atmosphere. Red arrows indicate

67

graphite particles adhered to the iron particles
Results and discussion
Figures 2(a) and 2(b) shows C K-edge
XANES spectra of iron powder milled underambient and Ar–H2 atmospheres, respectively,
as a function of glazing angle of the SR (seethe insets of Figure 2(a) and (b)). Sharp peaks
observed at 284.8 eV were assigned totransitions from C 1s orbitals to the unoccupied* orbitals originating from the basal plane of
the graphite. For comparison, iron particles weremilled in the absence of graphite and thespectrum of the milled iron particles did notshow the peak at 284.8 eV. Therefore, the peakat 284.8 eV was assigned to graphite milled withiron particles. With a decreasing in glazing
angle, the relative intensity of the * peakincreased gradually in the spectra of both
samples. However, the angle dependency of therelative intensity of the * peak differed,indicating a difference in orientation strength of
the graphite basal plane on the iron surfaces.

bonds, whereas * states are insensitive to theangle of incidence of the light [3]. Therefore, the*/ * peak ratios in the spectra of HOPG andcarbon black show the strongest and weakest
angle dependency, respectively. The ratio of theiron particles milled under an Ar–H2 atmosphereshows a stronger dependency than that of theiron particles milled under ambient atmosphere.
These
findings
indicatethatthemechanochemically prepared samples affect the
crystallographic orientation of the graphite on
their surface.

(a)Fig. 3 The */ * peak height ratio in the spectraof HOPG, graphite, and carbon black plotted asfunctions of cos2 .

(b)Frictional force on the milled iron particles
was measured using a lateral modulation friction
force microscope [4]. The frictional force on thesurface of the iron milled in Ar–H2 atmosphereis higher than that of the iron milled in ambient
atmosphere, although the data are not shown
here. The results obtained from XANES
measurements
revealedthat
themechanochemically prepared iron surface
affects the crystallographic orientation ofgraphite, and graphite orientation is known toplay an important role in determining its
lubricating behavior.

Fig. 2 Incident-angle-dependent C K-edge
XANES spectra of iron/graphite composite
particles milled under (a) ambient and (b) Ar-H2
atmospheres.
Figure 3 shows the */ * peak ratios as afunction of cos2 for highly oriented pyrolytic
graphite (HOPG), the graphite, iron particles
milled under ambient and Ar–H2 atmospheres,and carbon black, which has no crystal
orientation. According to the dipole selection
rules, the peak intensity associated with the *states follows a cosine-squared dependence withthe glazing angle between incident light and theReferences[1]M. K. Beyer, H. Clausen-Schaumann, Chem.
Rev. 105, 2921-2948 (2005).
[2] R. A. Rosenberg, P. J. Love, V. Rehn, Phys.
Rev. B 33, 4034 (1986).
[3]J. Kikuma, BP, Tonner, J. Electr. Spectrosc.
Relat. Phenom. 82, 53-60 (1996).
[4]S. Miyake, M. Wang, S. Ninomiya, Surf. Coat.
Technol., 200, 6137-6154 (2006).

68

C-, N-, O-XANES analyses of complex organic matterproduced by laboratory simulations of aqueous alteration
in meteorite parent bodies
Yoko Kebukawa1, Shusuke Misawa1, Shinya Asano1, Yasuji Muramatsu2, Sohta Hamanaka2, Yuki Tobita2,
Isao Yoda3, and Kensei Kobayashi1
1
Yokohama National University, 2University of Hyogo, 3Tokyo Institute of Technology
Abstract
We conducted C, N, O K-edge X-ray absorption near edge structure (XANES) analyses at
BL10, NewSUBARU for complex suites of organic compounds synthesized by simulating
experiments for aqueous alteration in meteorite parent bodies. Mixture of formaldehyde andammonia solutions were irradiated by gamma-ray or heated at 80-150 °C, to evaluate theeffects of irradiation and heating in the meteorite parent bodies during aqueous alteration. The
C-, N-, O-XANES characteristics of the reaction products were different between gamma-ray
irradiation and heating, and thus indicated that both have contributed for formation of diverse
organic compounds.
Introduction
Primitive
meteorites,suchascarbonaceous chondrites contain a few wt.%
organic matter. The most of organic carbon (>70
wt.%C) exists as in the form of solvent insolubleorganic
matter(IOM)
withcomplexmacromolecular structures. Rest of the organiccarbon is in the form of solvent extractableorganic compounds that include tens of
thousands of different molecular compositions,with possibly millions of diverse structures [1].
Some of them, such as amino acids andnucleobases could have been contributed to theemergence of life in the early earth. The origins
and formation processes of these diverse
extraterrestrial organic matter were not wellconstrained.
Cody et al. [2] proposed IOM formation
via formose reaction starting with formaldehyde
and glycolaldehyde during aqueous activity inthe small bodies. Additional hydrothermal
experiments showed that ammonia enhanced theyields of IOM like organic matter [3] andproductions of amino acids [4].
The most effective heat source during
aqueous alteration is considered to be the decayof short-lived radioactive nuclides such as 26Al
[5]. We have been evaluating effects of
gamma-ray from decay of short-lived
radioactive nuclides on formation of aminoacids that are recovered after acid hydrolysis ofexperimental products. Here we analyzed thereaction products from gamma-ray irradiations
which contain precursors of amino acids, using
C, N, O K-edge X-ray absorption near edge
structure (XANES) spectroscopy at BL10,NewSUBARU.

Experimental
Mixtures of water, formaldehyde andammonia in ratio of 100 : 5 : 5 (mol) simulating
primordial materials in comets and asteroids
were irradiated by gamma-ray (up to 45 kGy)
using 60Co gamma-ray source at Tokyo InstituteofTechnology.
Mixtureswithsame
compositions were heated under various
temperatures (80-150 °C) for comparison. The
experimental products were dried on Au plates
and analyzed using C-K, N-K, O-K X-ray
absorption near-edge structure (XANES).
Results
C-XANES spectra of the reaction
products showed peaks at 284.0 eV assigned toalkenes, 286.0 eV assigned to ketones, 287.0 eV
assigned to phenols and/or aliphatics, 288.8 eV
assigned to carboxyls and/or esters, and 290.0
eV assigned to carbamoyls and/or carbonates(Fig. 1). N-XANES spectra of the reaction
products showed peaks at around 399 eV
assigned to imines, and around 401 eV assigned
to amides (Fig. 2).
The gamma-ray irradiation products
contain more alkenes and less O-bearing
compounds compared to products from heating
experiments. The results indicated that organic
compounds formed by the gamma-ray
irradiation to the formaldehyde and ammonia
water solutions were significantly different fromthose produced by heating, thus the reaction
mechanisms would be different between
gamma-ray irradiation and heating. N-XANES
showed that all products contain amides, and69

thus these amide bonds likely produce aminoacids by acid hydrolysis.

Conclusions
We successfully obtained functional group
analysis of laboratory synthesized organic
matter simulating aqueous alteration of
meteorite parent bodies using C,N,O-XANES at
BL10/NS. In addition to other analyses
including infrared spectroscopy and mass
spectrometry, these results will help tounderstand nature and chemistry of the complex
organic matter synthesized during aqueousalteration.
References[1] P. Schmitt-Kopplin, Z. Gabelica, R. D.
Gougeon, A. Fekete, B. Kanawati, M. Harir, I.
Gebefuegi, G. Eckel, N. Hertkorn, PNAS, 107,2763 (2010).
[2] G. D. Cody, E. Heying, C. M. O. Alexander, L.
R. Nittler, A. L. D. Kilcoyne, S. A. Sandford, R. M.
Stroud, PNAS, 108, 19171 (2011).
[3] Y. Kebukawa, A. L. D. Kilcoyne, G. D. Cody,
The Astrophysical Journal 771, 19 (2013).
[4] Y. Kebukawa, Q. H. S. Chan, S. Tachibana, K.
Kobayashi, M. E. Zolensky, Science Advances, 3,e1602093 (2017)[5] A. J. Brearley, In Meteorites and the Early Solar
System II (eds. D. S. Lauretta and J. H. Y.
McSween), pp. 587-624 (2006).

Fig. 1 C-XANES of the products from gamma
ray irradiation and heating of formaldehyde andammonia water solutions.

Fig. 2 N-XANES of the products from (a)gamma ray irradiation and (b) heating offormaldehyde and ammonia water solutions.

70On-chip Synthesis of Ruthenium Complex byMicrowave-Induced Reaction in a Microchannel Coupled with
Post-Wall Waveguide
Yuichi Utsumi1, Akinobu Yamaguchi1, and Mitsuyoshi Kishihara2
Laboratory of Advanced Science and Technology for Industry, University of Hyogo
2
Okayama Prefectural University

1

Abstract

We demonstrate the on-chip synthesis of a ruthenium complex based on a microwave-induced
reaction in a microchannel coupled with a post-wall 24.15 GHz waveguide. The chip structure forcontinuous microwave irradiation of solvents and reactants comprises a post-wall waveguide and a
microchannel that enters and exits the waveguide by passing between the metallic posts. After
microwave irradiation of the microfluidic channel, the specific fluorescence emission spectrum ofTris (2,2'-bipyridyl) ruthenium(II) is observed.

Introduction

Experiments

Microwave heating is recognized as the leading
method for inducing chemical synthesis with very
high reaction rates and yields [6]. Theseadvantages are due to the specific effects of
microwave radiation on molecular motion (forexample, ion migration and dipole rotation),
which accelerates the reaction steps. To obtain
multiple sequential and combinatorial chemical
reactions with a small amount of source reagentsand products in a reduced-size system, apromising approach is lab-on-a-chip (LOC) andmicrofluidics
includingmicroreactor
technology. . However, by microwave heating
combined with microfluidics, extremely highreaction rates and yields should be possible in amore sequentially integrated chemical-synthesis
platform that offers extremely precise control of
the reaction. Unfortunately, few reports exist on
microreactors wherein chemical and biochemical
reactions are induced by microwaves. To address
this issue, we demonstrate in the present work the
on-chip synthesis of a ruthenium complex
achieved by a microwave-induced reaction in a
microfluidic channel inside a post-wall waveguidedesigned to confine 24.15 GHz microwave
radiation.
In this work, we propose a chip-size structurethat allows continuous microwave irradiation todrive radiation-induced chemical synthesis. The
structure consists of a post-wall waveguide and a
microchannel that passes between the metallic
posts. The temperature of water, ethanol, acetylacetone, etc. under microwave irradiation are
examined both numerically and experimentally byconsidering microwave sources of approximately
3 W. We also describe the on-chip synthesis of aruthenium complex based on microwave-induced
reactions in a microchannel inside a 24.15 GHz
post-wall waveguide.

Based on the design considerations, wefabricated a micro chemical chip for
microwave-induced synthesis and measured thewater temperature during microwave irradiation.
Figure 1 shows the fabricated microreactor chip,
which comprised three 1.0-mm-thick sheets ofPTFE stacked to form the microfluidic channel.
Finally, sub-miniature type A (SMA) connectors
were attached for use as input and output ports.
For impedance matching, a 50 Ω dummy load wasconnected to the output port. The curved

Fig.1 Photograph of fabricated structure of
microchip of which microchannel is embedded in
the post-wall waveguide.
microfluidic channel was fabricated by machining
thecentralPTFE
sheet,
anda
1.0-mm-internal-diameter PTFE tube was laid in
the microchannel to assist the flow of reagent into
the channel. The water temperature was measured
with an optical-fiber microscope (FS100-2M,
Anritsu-Meter Co., Ltd.) under 24.15 GHz
microwave irradiation with a power of 0.7 and 1.2
W. In this work, the microwave radiation was
produced by amplifying the output of a 24.15
GHz Gunn oscillator up to 0.7 and 1.2 W. An
isolator was inserted to prevent the microwave
power from returning to the amplifier. . When
inputting 3.0 W of microwave power, thetemperature increases to 75.9 °C.

71

Results and discussion

only 120 s. The conventional method forsynthesizing Tris (2,2'-bipyridyl) ruthenium(II) by
heating in an oil bath requires several tens of hours.
These

The experimental results indicate that the solvent in
the microfluidic channel is heated by microwave
irradiation with an input power of about 3.0 W or less.
The present configuration of the microfluidic channel
and post-wall waveguide is suitable for heating
several microliters of solvent, so this assembly
qualifies as a chip-size microreactor. Next, we
synthesizedtris(2,2’-bipyridine)ruthenium(II)perchlorate
trihydrate([Ru(bpy)3](Cl4)2･3H2O) inthis microreactor by using
the following microwave
irradiationinducedchemical reaction.
RuCl ･3H O + bpy

Fig.2
Fluorescence emission spectra of the
products after microwave irradiation and starting
materials before irradiation.

Ru(bpy)The microchip for this synthesis was prepared as
described above, and the microwave frequency andpower were 24.15 GHz and 3.0 W. The irradiation
time was 120.0 or 600.0 s, and an optical-fiber sensor
was used to monitor the temperature of the
microchannel during microwave irradiation. The
temperature was fixed at 70 °C for this synthesis
procedure. After the synthesis induced by microwave
irradiation, the initially green solution becomes orange
red. The fluorescence emission spectra ofTris(2,2'-bipyridyl)ruthenium(II) dissolved in water
was acquired by using USB2000 and DH2000
instruments (Ocean Optics Co. Ltd.).
The mixture of RuCl3 ･3H2O(0.25g;1.03 mmol)and 2,2’-bipyridine (bpy) (0.797g;5.09 mmol) in
ethylene glycol (11.1 ml) was preparedas thestarting materials for the synthesis of([Ru(bpy)3](Cl4)2･3H2O). The irradiation time was120.0 s. The fluorescence peak of the products
appears at 607 nm, which is the specific peak ofTris(2,2'-bipyridyl)ruthenium(II) [42,43]. We also
conducted microwave-induced synthesis of Tris
(2,2'-bipyridyl)ruthenium(II) from the samestarting material by using a commercial
microwave source with a frequency and power of
2.45 GHz and 200.0±4.0 W (SHARP Co. Ltd.,RE-TD1, irradiation time: 180.0 s) and compared
the fluorescence spectra of the products with thoseof the products synthesized as described above.
The wavelength of each fluorescence peak of Tris
(2,2'-bipyridyl)ruthenium(II) (λ1 = 607 nm, λ2 =758 nm) coincides with that of the products
synthesized in the proposed microreactor. The
reaction yield is estimated to ~85.7% bycomparing the saturated magnitude of the 607 nm
fluorescence peaks of the products synthesized by
the commercial microwave source.
We
also
producedtheTris(2,2'-bipyridyl)ruthenium(II) by irradiating forresults show that on-chip microwave-induced
synthesis of Tris (2,2'-bipyridyl)ruthenium(II)occurs in the microfluidic channel with a high rate
and yield [2].
Conclusion
In this work, we demonstrate the on-chip synthesis ofa ruthenium complex by using a microwave-induced
reaction in a microfluidic channel integrated into a
post-wall waveguide designed to contain 24.15 GHz
microwave radiation. PTFE is used as the dielectricmaterial wherein the microwaves propagate because itis an excellent chemical container owing to its low
dielectric loss, high resistance to heat load (up to
300 °C), and chemical inertness. For this synthesis,
the microwave frequency and power in the waveguidewere 24.15 GHz and 3.0 W, the irradiation time was120.0 or 600.0 s, and the solvent temperature was
70 °C. After microwave irradiation, the reaction
products exhibit the specific fluorescence spectrum ofTris (2,2'-bipyridyl) ruthenium(II). Thus, this work
demonstrates that a microwave-induced reaction in
microfluidic channel integrated into a 24.15 GHz
post-wall waveguide can be used for on-chip synthesisof a ruthenium complex with a high reaction rate andyield.

References[1] P.L.Spencer, U.S.Patent 2 605 383,1952.
[2] Y .Utsumi et al., Sensors and Actuators B
242, 384-388 (2017).

72

Caltrop particles synthesized by X-ray radiolysis usingsynchrotron radiation
Akinobu Yamaguchi1, Ikuo Okada2, Ikuya Sakurai2, Takao Fukuoka1, and Yuichi Utsumi1
1
Laboratory of Advanced Science and Technology, University of Hyogo
2
Synchrotron Radiation Research Center, Nagoya University

Abstract

We report the synthesis of caltrop cupric oxide particles from the Cu(CH3COO)2 solution with anadditive alcohol by X-ray radiolysis using synchrotron radiation. The particles were characterizedby high-resolution scanning electron microscopy and micro-Raman spectrometry. These results
indicate there are several synthetic routes to obtain caltrop particles and demonstrate the behaviorof three-dimensional printers, enabling us to build composite material structure with metallic andother materials.

Introduction
The synthesis of various metallic and oxide
particles has attracted considerable attention
owing to the potential applications of functional
nano- or micro-scale particles in various fields
such as catalysis, medicine, electronics andoptical-devices engineering. Recently, metallic
and oxide particles have been synthesized via
mnumerous methods such as sonochemical
reaction, chemical reduction of metallic ions inaqueous solutions, and laser ablation andlaser-induced photochemical reactions, etc.
X- or -ray irradiation has also been
investigated as a radiation-assisted synthesis ofgold particles on a silicon substrate wasreported by Rosenberg and coworkers [1] andYamaguchi et al.[2] In particular, thesynchrotron radiolysis of these particles has
also become a focus in engineering applications
because it enables the generation of theseparticles from aqueous solutions of metallic
salts. In addition, nano- or micro-scale structure
consisting of functional materials can be
tailored by immobilizing theses particles at atarget location.
Cupric oxide (Cu2O, CuO) particles which
are p-type semiconductor materials with a low
band energy have recently attracted muchattention because the particles have been usedin the anodes of lithium ion cells and pH
sensors. The cupric particles have favorable
characteristics;
theyarenon-toxic,
environmentally friendly, highly stable andrecyclable.
We
demonstratethesynthesisofmicrometer-and submicrometer-scale cupricoxide (Cu2O, CuO) particles using the X-ray
synchrotron radiolysis from cupper (II) acetate
Cu(CH3COO)2 solution. The synthesized cupricoxide particles exhibit unique morphologies
that resemble caltrops, which are antipersonnel
weapons made up of two or more sharp nails or

spines; they have traditionally been used toslow the advance of horses, war elephants andhuman troops. They are often called “makibishi”
in Japan, one of Ninja tools to damage thewheels of vehicles.
Experiments
The stock solution was made by dissolving
6.8 g of Cu(CH3COO)2 (Wako Chemical,
99.99%) in 100 mL of doubly distilled water.
We syphoned off 200 L of the solution into a
microtube and added 10 L ethanol to obtain

Fig. 1 Experimental setup for the X-ray irradiation of
the Cu(CH3COO)2 solution.

the mixed solution. An 18 L aliquot of themixed solution was then exposed to X-ray
irradiation as schematically shown in Fig. 1. In
this study, a silicon substrate was dipped into
the mixed solution and the specimen was placedon the irradiation system. The specimen was
exposed to 5 min of X-rays and then washedusing deionized water. The synthesizedparticles deposited on the silicon substrate were
examined by field emission scanning electron
microscopy with energy dispersive X-ray
spectroscopy (EDX). In addition, we obtained
Raman spectra using a micro-Raman
spectrometer to determine the material
characteristics of the synthesized particles.

73

Results and discussion
No particles were synthesized when the silicon
substrate was immersed in an aqueous
Cu(CH3COO)2 solution without ethanol andthen exposed to X-rays. When ethanol wasadded to the Cu(CH3COO)2 solution, we obtain
the particles immobilized on the substrate as
typically shown in Fig. 2. [2]Elementary analysis using EDX suggests that

Fig. 4 The average and standard deviation of length ofcaltrop particles as a function of the fraction of ethanol.

scattering spectra in Fig. 3. The Raman spectra
is expected to be derived from Cu and CuO.
The SEM images were also used to evaluate
the average length of length of caltrop particles.
Figure 4 summarizes ethanol fraction
dependence of length of caltrop particles. The
average length and standard deviation of thelength depended on the concentration of ethanol,
up to saturation concentration of 1/20. This
trend was qualitatively predicted by typicalreaction kinetics, whereby the added ethanolshows the reaction by adsorbing onto thesurface of particles, preventing their growth.

Fig. 2 SEM images of synthesized particles on silicon
substrate dipped in an aqueous Cu(CH3COO)2 solution
with ethanol.

the caltrop particles comprise a mixture of
species, such as Cu, CuO, Cu2O and Cu4O3. To
determine the composition of the cupric oxide
particles, we measured the micro-lase Raman

Conclusion
The present work demonstrate that cupricparticles can be obtained via a one-step
synthesis in which an aqueous Cu(CH3COO)2
solution mixed with ethanol is exposed to X-ray
irradiation at a synchrotron source. Using SEM
microscopy and Raman spectroscopy, we
determine that the caltrop particles comprise Cu
and CuO. The alcohol that is added to the sticksolution enables the copper ions to reduce thecaltrop particles. This method can also provide
novel lithography process to construct theadditional nanostructures onto the previously
patterned area.
References[1] R. A. Rosenberg et al., J. Vac. Sci. Technol.
B 16, 3535 (1998); Q. Ma et al., Appl. Phys.
Lett. 76, 2014 (2000).
[2] A. Yamaguchi et al., Mater. Chem. Phys. 160,
205 (2015); Jpn. J. Appl. Phys. 55, 055502(2016); J. Nanometer. 8584304 (2016); J.
Synchrotron Radiation 24, 653 (2017).

Fig. 3 Micro-laser Raman spectra of synthesizedparticles on (a) Si substrate and SiN membrane,
respectively.

74

High efficiency mixing for Lab-on-a-disk platformby utilizing Euler force
Masaya Takeuchi, Akinobu Yamaguchi, Yuichi Utsumi
Laboratory of Advanced Science and Technology, University of Hyogo

Abstract

Mixing of liquids in micro scale is generally difficult because a liquid unlikely to be turbulent flow,
dominated by the viscous force. A mixing utilizing Euler-force can be applied to various
application because the flow path structure is very simple. In previous research, this mixing
method has been investigated for liquids of the same density. However, the investigation has notbeen performed for liquids of the different density. In this study, we examined the above
effectiveness.

Introduction
Lab-on-a-disk, which controls solution by therotation of the device, has drawn a great deal ofinterest in the field of microfluidic device. It isstable for chemical change of solution
compared with liquid control by electrophoresis,
and enables to form complex microfluidic
network compared with liquid drive by syringe
and peristaltic pumps. From above, it isexpected in various field such as medical,
biochemistry and environment. To construct a
chemical reaction system on Lab-on-a-disk, it isessential that a mixing of liquids was performedin micro flow channel and reservoir. However,
the mixing in micro scale is generally difficult
because a liquid is unlikely to be turbulent flow,
dominated by the viscous force. To solve thisproblem, a mixing methods using magnetic
beads, Coriolis force and Euler force were
presented so far. Especially Euler-force-mixing
can be applied to various application because it
is simple flow-path-structure and only
performed by the rotation control of the device.
Euler-force is inertial force on rotating
coordinate system which occurs perpendicularly
to the radial direction depending on angularacceleration, and is given as

Lab-on-a-diskωEuler-force

VortexFig. 1. Principle of Euler-force-mixing

Experiment
In this experiment, we used colored purewater (1.00 g/cm2) and 1M phosphoric acid
(1.05 g/cm2). The evaluation of the mixing was
performed by a standard deviation of gray scaleof the shot image. The reservoir, where
Euler-force-mixing was performed, wasfabricated by punching. The diameter is 3 mm
and the depth is 2.5 mm. Repeated Acceleration/ deceleration of angular velocity is 1000 rpm/s
for 1 second respectively.

=

where r is the distance from the center ofrotating coordinate system, and ω is angularfrequency. The principle of the mixing is shownin Fig. 1. The magnitude of Euler-force depends
on the distance from the center of rotating
coordinate system, and liquids are mixed byutilizing the difference of these forces.
In previous research, this mixing method
were investigated for liquids of the samedensity numerically and experimentally [1].
However, the investigation has not been
performed for liquids of the different density. In
this study, we examined the above
effectiveness.

Result and discussion
The standard deviation dependence on thenumber of this cycles is shown in Fig. 2. It was
confirmed that the standard deviation decreases
with increases of that cycles. It was 2.4 at 30
cycles. This value is almost the same as astandard deviation where these liquids is fully
mixed. Therefore, we have confirmed theeffectiveness of Euler-force-mixing for liquidsof the different density.

75

Standard deviation

35

Colored water volume : 6 µL

30

1M phosphoric acid volume : 6

25
20
15
10
5
0

0

10
20
Number of cycles

30

Fig. 2. Standard deviation dependence on
number of cycles of acceleration / deceleration(1000 rpm /s) for 1 second respectively.

Conclusion
We investigated the effectiveness ofEuler—force-mixing for liquids of the different
density. As a result, we have confirmed thatliquids with a specific gravity difference of 5 %can be mixed. It is expected that this mixing

method can be further applied to various
application

References[1] Yong Ren, Wallace Woon-Fong Leung,International Journal of Heat and Mass
Transfer, 60, pp. 95-104 (2013).

76

Part 3. List of Publications“Experiments of Material Engineering III” for third-year students in
School of Engineering

(1) Papers

List of publications

1.

"Production of Medical 99mTc Isotope Via Photonuclear Reaction"
M. Fujiwara, K. Nakai, N. Takahashi, T. Hayakawa, T. Shizuma, S. Miyamoto, G. T. Fan, A. Takemoto, M.
Yamaguchi, and M. Nishimura
Physics of Particles and Nuclei, 2017, 48, No. 1, pp. 124–133. © Pleiades Publishing, Ltd., 2017.

2.

"Effect of the nuclear medium on α-cluster excitation in⁶Li"
T. Yamagata, S. Nakayama, H. Akimune, and S. Miyamoto
Physical Review C, 95, pp.044307-1-10 (2017).

3.

"Coherent radiation at the fundamental frequency by a Smith-Purcell free-electron laser with dielectric
substrate"
D. Li, Y. Wang, M. Nakajima, M. Tani, M. Hashida, M. R. Asakawa, Y. Wei, and S. Miyamoto
Appl. Phys. Lett. , 110, 151108-1-3 (2017).

4.

"Direct neutron-multiplicity sorting with a flat-efficiency detector"
H. Utsunomiya, I. Gheorghe, D. M. Filipescu, T. Glodariu, S. Belyshev, K. Stopani, V. Varlamov, B. Ishkhanov,
S. Katayama, D. Takenaka, T. Ari-izumi, S. Amano, S. Miyamoto
Nuclear Instrum. Methods Phy. Res. A, 871, pp. 135-141 (2017).

5.

"Measurement of deflection on germanium and gold prisms using 1.7 MeV laser Compton scattering γ-rays"
T. Kawasaki, S. Naito, Y. Sano, T. Hayakawa, T. Shizuma, R. Hajima, S. Miyamoto
Physics Letter A, vol. , 381, Issue 36, pp. 3129-3133 (2017).

6.

"Low-lying Dipole Strength in 52Cr"
T. Shizuma, T. Hayakawa, I. Daito, H. Ohgaki, S. Miyamato, and F. Minato
Physical Review C, 96, 044316 (2017).

7.

"Photoneutron cross section measurements in the 209Bi(γ, xn) reaction with a new method of direct
neutron-multiplicity sorting"
I. Gheorghe, H. Utsunomiya, S. Katayama, D. Filipescu, S. Belyshev, K. Stopani, V. Orlin, V. Varlamov, T.
Shima, S. Amano, S. Miyamoto, Y.-W. Lui, T. Kawano, and S. Goriely
Physical Review C, 96, 044604 (2017).

8.

"Structural analysis of amorphous carbon films by BEMA theory based on spectroscopic ellipsometry
measurement"
XiaoLong Zhou, Satoru Arakawa, Sarayut Tunmee, Keiji Komatsu, Kazuhiro Kanda, Haruhiko Ito, andHidetoshi Saitoh
Diamond & Related Materials 79C (2017) 46-59.

9.

"Soft X-ray irradiation effect on the fluorinated DLC film"
Hiroki Takamatsu, Masahito Niibe, XiaoLong Zhou, Keiji Komatsu, Hidetoshi Saitoh, Hiroki Akasaka, Akihiro
Saiga, Koji Tamada, Masahito Tagawa, Kumiko Yokota, Yuichi Furuyama, and Kazuhiro Kanda
Diamond & Related Materials 79C (2017) 14-20.

10. "Formation of nanocrystalline silicon in SiOx by soft X-ray irradiation at low temperature"
Akira Heya, Fumito Kusakabe, Naoto Matsuo, Kazuhiro Kanda, Kazuyuki Kohama, and Kazuhiro Ito
Japanese Journal of Applied Physics 56 (2017) 035501.
11. "Modification Processes of Highly Hydrogenated Diamond-Like Carbon Thin Films by Soft X-ray
Irradiation"
Kazuhiro Kanda, Ryo Imai, Masahito Niibe, Hisashi Yoshioka, Keishi Komatsu, and Hidetoshi Saitoh
Sensors and Materials, 29 (2017) 817-826.

791

12. "Structural analysis of amorphous carbon films by spectroscopic ellipsometry, RBS/ERDA, andNEXAFS"
XiaoLong Zhou, Tsuneo Suzuki, Hideki Nakajima, Keiji Komatsu, Kazuhiro Kanda, Haruhiko Ito, and Hidetoshi
SaitohAppl. Phys. Lett. 110 (2017) 201902.
13. "Fabrication of DLC cone for fast ignition experiment"
Mayuko Koga, Kazuhiro Kanda, Tsuneo Suzuki, and Takayoshi Norimatsu
Fusion Engineering and Design, 123 (2017) 120-123.
14. "ダイヤモンドをよく知るために ～量子ビーム利用測定技術（１） X 線吸収分光を用いた局所構造
解析"
神田一浩
NEW DIAMOND, 126 (2017) 37-40.
15. "ＤＬＣ膜構造分析とＩＳＯ規格化"
神田一浩
応用物理, 86 (2017) 558-564.
16. "Characteristics of TiO2 thin film surfaces treated by O2 Plasma in dielectric barrier discharge with theassistance of external heating"
Retsuo Kawakami, Masahito Niibe, Yoshitaka Nakano, Yuma Araki, Yuki Yoshitani, Chisato Azuma, Takashi
Mukai
Vacuum, 152, 265-271 (2018). doi: 10.1016/j.vacuum.2018.03.051
17. "Nano-polycrystalline diamond synthesized from neutron-irradiated highly oriented pyrolytic graphite(HOPG)"
Mititaka Terasawa, Shin-ichi Honda, Keisuke Niwase, Masahito Niibe, Tomohiko Hisakuni, Tadao Iwata, Yuji
Higo, Toru Shinmei, Hiroaki Ohfuji, Tetsuo Irifune
Diamond & Related Materials, 82, 132-136 (2018).
18. "Quenchable compressed graphite synthesized from neutron-irradiated highly oriented pyrolytic graphite
in high pressure treatment at 1500°C"
Keisuke Niwase, Mititaka Terasawa, Shin-ichi Honda, Masahito Niibe, Tomohiko Hisakuni, Tadao Iwata, Yuji
Higo, Takeshi Hirai, Toru Shinmei, Hiroaki Ohfuji, Tetsuo Irifune
J. Appl. Phys. 123, 161577 (2018).
19. "Characteristics of N2 and O2 Plasma-Induced Damages on AlGaN Thin Film Surfaces"
Retsuo Kawakami, Masahito Niibe, Yoshitaka Nakano, Ryo Tanaka, Chisato Azuma, Takashi Mukai
Phys. Status Solidi, A214, 1700393 (2017).
20. "Generation of electrical damage in n-GaN films following treatement in a CF4 plasma"
Yoshitaka Nakano, Retsuo Kawakami, Masahito Niibe
Appl. Phys. Express, 10, 1162021 (2017).
21. "TiO2 Thin Film Surfaces Treated by O2 Plasma in Dielectric Barrier Discharge with Assistance of Heat
Treatment"
Retsuo Kawakami, Kengo Fijimoto, Masahito Niibe, Yuma Araki, Yoshitaka Nakano, Takashi Mukai
Proc. 14th Int’l Symp. Sputtering & Plasma Processes (ISSP 2017), 274-277 (2017).
22. "Laser plasma soft X-ray source based on cryogenic target"
S. Amano
Proc. of SPIE, vol.10243, 10243Q (2017)280

23. "クライオターゲットによる「水の窓」レーザ生成プラズマ軟 X 線源"天野壮
電気学会論文誌 C, Vol.137, No.3, 406-410(2017)24. "Terahertz spectroscopy of graphene complementary split ring resonators with gate tenability"
Satoru Suzuki, Yoshiaki Sekine, and Kazuhide Kumakura
Japanese Journal of Applied Physics 56, 095102-1-5 (2017).
25. "Initial stage of hexagonal boron nitride growth in diffusion and precipitation method"
Satoru Suzuki, Yui Ogawa, Shengnan Wang, Kazuhide Kumakura
Japanese Journal of Applied Physics 56, 06GE06-1-5 (2017).
26. "Depth analysis of molecular orientation induced by nanoimprint graphoepitaxy"
M. Okada, R. Fujii, Y. Haruyama, H. Ono, N. Kawatsuki, and S. Matsui
Jpn. J. Appl. Phys. 56 040302, 201727. "Formation of complex molecular orientation patterns in nanostructures via double nanoimprint
graphoepitaxy"
Makoto Okada, Ryosuke Fujii, Yuichi Haruyama, Hiroshi Ono and Nobuhiro Kawatsuki
Appl. Phys. Express 10, pp. 105201, 201728. "A study on enhancing EUV resist sensitivity"
Atsushi Sekiguchi, Tetsuo Harada, Takeo Watanabe
Proc. SPIE 10143 (2017) 1014322.
29. "ニュースバル放射光施設を活用したフォトマスク検査顕微鏡の開発"
原田哲男
姫路工業倶楽部部報工学レポート vol. 28, 2017/1/1.
30. "集光型コヒーレント回折イメージング法による EUV マスク上の欠陥評価法の開発"
原田哲男，橋本拓，渡邊健夫
電気学会論文誌 A, 137 (5), pp.260-264 (2017).
31. "Imaging performance improvement of coherent extreme-ultraviolet scatterometry microscope withhigh-harmonic generation extreme-ultraviolet source"
D. Mamezaki, T. Harada, Y. Nagata, and T. Watanabe
Jpn. J. Appl. Phys. 56, 06GB01 (2017).
32. "Observation of EUVL mask using coherent EUV scatterometry microscope withhigh-harmonic-generation EUV source"
D. Mamezaki, T. Harada, Y. Nagata, and T. Watanabe
Proc. SPIE 10454 (2017)1045413.
33. "Resist Investigation Method using ab initio MO Calculation on basis of Approximation Molecular
Model"S. Nagata, S. Niihara, T. Harada, and T. Watanabe
J. Photopolym. Sci. Technol. 30 (2017) 583.
34. "Absorption Coefficient Measurement Advanced Method of EUV Resist by Direct-Resist Coating on a
Photodiode"S. Niihara, D. Mamezaki, M. Watanabe, T. Harada, and T. Watanabe
J. Photopolym. Sci. Technol. 30 (2017) 87.
3

81

35. "Evaluation of Block Copolymer Structure using Soft X-Ray Scattering"
Y. Nakatani, T. Harada, A. Takano, M. Yamada, and T. Watanabe
J. Photopolym. Sci. Technol. 30 (2017) 77.
36. "原子状水素を用いた Ni コートミラーの炭素汚染の除去"
新部正人，原田哲男，部家彰，渡邊健夫，松尾直人
第 78 回応用物理学会秋季学術講演会予稿集，5a-S44-2 (2017).
37. "軟 X 線散乱を用いたトリブロック共重合体構造の評価"
中谷侑亮，原田哲男，高野敦志，山田素行，渡邊健夫
第 78 回応用物理学会秋季学術講演会予稿集，5p-S42-3 (2017).
38. "軟Ｘ線 CMOS イメージセンサの特性評価"
原田哲男，中谷侑亮，寺西信一，渡邊健夫
第 78 回応用物理学会秋季学術講演会予稿集，5p-S42-4 (2017)39. "フォトダイオード直接塗布法による EUV レジストの高精度な吸収係数測定法"
新原章汰，豆﨑大輝，渡辺雅紀，原田哲男，渡邊健夫
第 78 回応用物理学会秋季学術講演会予稿集，5p-S42-5 (2017)40. "Synthesis of Hyperbranched Polyacetals containing C-(4-t-butylbenz)calix[4]resorcinarene; Resist
Properties for Extreme Ultraviolet (EUV) Lithography"
Hiroto Kudo, Mari Fukunaga, Kohei Shiotsuki, Hiroya Takeda, Hiroki Yamamoto, Takahiro Kozawa, Takeo
Watanabe
Reactive and Functional PolymersREACT-D-18-00010.
41. "半導体微細パターニング技術最前線（共著）～基礎から MEMS 技術、応用開発事例まで～
第 2 章 EUV リソグラフィ技術、第 2 節 EUV 干渉露光技術"
渡邊健夫
株式会社エヌ・ティー・エス，2017.4.10.
42. "EUV レジストの最前線（特集「第 16 回放射線プロセスシンポジウムの各論として掲載）"
渡邊健夫「放射線と産業」第 142 号，一般財団法人 放射線利用振興協会編
43. "最新フォトレジスト材料開発とプロセス最適化技術" 河合晃 監修
渡邊健夫（株）シーエムシー出版，2017.9.
44. "ＵＶ硬化技術を使った新製品開発（共著）第 8 章 UV 硬化型ソルダーレジスト、フォトレジストの設計と評価
第 7 節 EUV レジストのアウトガス評価、反応解析"
渡邊健夫
株式会社技術情報協会，2017.11.
45. "Synthesis of cupric particles induced by X-ray radiolysis"
A. Yamaguchi, I. Okada, T. Fukuoka, Y. Utsumi
IEEJ Transactions on Electronics, Information and Systems, vol. 137, No.3, pp. 400 -405 (2017), DOI:
10.1541/ieejeiss.137.400"X 線照射による銅粒子生成"山口明啓，岡田育夫，福岡隆夫，内海裕一
電気学会論文誌 C（電子・情報・システム部門誌）
46. "A study for Sensitivity Improvement of 3-D Lab-on-a-CD based Immunosensor"
482

Chiwa Kataoka, Tsukasa Azeta, Kazuyuki Sawadaishi, Yoshiaki Ukita, Akinobu Yamaguchi and Yuichi Utsumi
IEEJ Transactions on Electronics Information and Systems Vol. 137 No.3, pp. 418 – 423 (2017), DOI:
10.1541/ieejeiss.137.418*Electronics and Communications in Japan, Vol. 101, No. 1, 2018 (Willey 英訳バージョン)
47. "On-chip Synthesis of Ruthenium Complex by Microwave-Induced Reaction in a Microchannel Coupledwith Post-Wall Waveguide"
Y. Utsumi, A. Yamaguchi, T. Matsumura-Inoue, and M. Kishihara
Sensors & Actuator B: Chemical, 242, 384-388 (2017).
48. "Interdigital Transducer Generated Surface Acoustic Waves Suitable for Powder Transport"
Tsunemasa Saiki, Akio Tsubosaka, Akinobu Yamaguchi, Michitaka Suzuki, Yuichi Utsumi
Advanced Powder Technology 28, 491-498 (2017).
49. "圧電体基板上に作製した NiCu 合金微小磁性細線の磁気抵抗効果"
山口明啓，大河内拓雄，保井晃，才木常正，内海裕一，木下豊彦，山田啓介
電気学会論文誌 A, Vol. 137 (No. 8), pp. 487-488 (2017).
IEEJ Transaction on Fundamentals and Materials Vol. 138 (No. 8), pp. 487-488 (2017).
50. "Caltrop particles synthesized by X-ray radiolysis in liquid phase with photochemical reaction"
A. Yamaguchi, I. Okada, I. Sakurai, T. Fukuoka, M. Ishihara and Y. Utsumi
Journal of Synchrotron Radiation 24, 653-660 (2017).
51. "Development of Bead-Based Multiplexed Immunoassay with Image Cytometric Analysis"
Yoshiaki Ukita, Chiwa Kataoka, Kazuyuki Sawadaishi, Akinobu Yamaguchi, and Yuichi Utsumi,
Sensors and Materials, Vol. 29 (No. 5), 567-573 (2017).
52. "Control of domain structure in artificial Ni wires fabricated on a LiNbO3 substrate"
A. Yamaguchi, T. Ohkochi, A. Yasui, T. Kinoshita, K. Yamada
IEEE Transactions on Magnetics 53, 8108504 (2017).
53. "X 線を用いた熱化学異方性エッチングによる PTFE の微細加工プロセスの検討"
山口明啓，木戸秀樹，竹内雅耶，内海裕一
電気学会論文誌 E, Vol. 137 (No. 12) pp. 417-421
54. "金ナノ粒子のボトムアッププロセスで表面増強ラマン散乱活性なナノセンサー／ナノビーコンを造る"
福岡隆夫，山口明啓，内海裕一，倉本亮介，森康維
BUNSEKI KAGAKU Vol. 66 No.2 pp. 919-923 (2017).
55. "Fabrication of Waveguide Butler Matrix for Short Millimeter-Wave by X-ray Lithography"
M. Kishihara, M. Takeuchi, A. Yamaguchi, Y. Utsumi, I. Ohta
IEEE 978-1-5090-6360-4 DOI: 10.1109/MWSYM.2017.8058629 Conference: Conference: 2017 IEEE/MTT-S
International Microwave Symposium - IMS 201756. "Biofilm Formation Behaviors on Graphene by E. coli and S. epidermidis"
H. Kanematsu, M. Sato, K. Shindo, D. M. Barry, N. Hirai, A. Ogawa, T. Kogo, Y. Utsumi, A. Yamaguchi, H.
Ikegai, Y. Mizunoe
ESC Transactions, 80(10), 1167-1175 (2017).
57. "Caltrop cupric oxide particles synthesized by X-ray photochemical reaction"
A. Yamaguchi, I. Okada, T. Fukuoka, and Y. Utsumi
2017 International Conference on Electronics Packaging (ICEP 2017) Conference Proceedings IEEE Xplore,sponsored by JIEP (The Japan Institute of Electronics Packaging),IEEE CPMT Society Japan Chapter, iMAPS.
583

58. "DIELECTROPHORESIS-ENABLED DYNAMIC FORMATION OF HIGHER-ORDER
NANOSTRUCTURE CONSISTING OF AU-NANOPARTICLES-DECORATED POLYSTYRENEBEADS FOR SERS DETECTION"
A. Yamaguchi, T. Fukuoka, and Y. Utsumi
Micro TAS 2017, W057c
59. "放射光励起光プロセスと新しい応用展開"
山口明啓, 内海裕一
公益社団法人 砥粒加工学会学会誌「特集 めっき技術における微細性」p535-538 (2017).
Journal of the Japan Society for Abrasive Technology Vo. 6, No. 10 (2017) Oct., pp. 535-538.
60. "研究室だより：兵庫県立大学 材料・放射光専攻ナノマイクロシステム研究室"
山口明啓
電気学会 E 部門誌 Vol. 138 (No. 2) , pp. 2

6

84

(2) International meetings
1.

"Performance measurement of HARPO: a Time Projection Chamber as a gamma-ray telescopeand polarimeter"
P. Gros, S. Amano, D. Atti ́e, P. Baron, D. Baudin, D. Bernard, P. Bruel, D. Calvet, P. Colas, S. Dat ́e, A.
Delbart, M. Frotin, Y. Geerebaert, B. Giebels, D. G otz, S. Hashimoto, D. Horan, T. Kotaka, M. Louzir, F.
Magniette, Y. Minamiyama, S. Miyamoto, H. Ohkuma, P. Poilleux, I. Semeniouk, P. Sizun, A. Takemoto,
M. Yamaguchi, R. Yonamine, and S. Wang
arXiv:1706.06483v1 [astro-ph.IM] 20 Jun 2017 (2017).

2.

"M1 strength in photonuclear reactions with linearly polarized γ-ray beam"
T. Hayakawa, T. Shizuma, K. Horikawa, S. Miyamoto, S. Amano, M. Yamaguchi, A. Takemoto, S. Chiba,
H. Akimune, K. Ogata, M. Fujiwara
JPS Conf. Proc. 14, 021012 (2017).

3.

"Measurement of neutron spectra for photonuclear reaction with linearly polarized photonsr"
Y. Kirihara, T. Itoga, T. Sanami1, H. Nakashima, Y. Namito1, S. Miyamoto, A. Takemoto, M. Yamaguchi,
and Y. Asano
EPJ Web of Conferences 153, 01019 (2017). DOI: 10.1051/epjconf/201715301019

4.

"Measurement of neutron energy spectra for Eg=23.1 and 26.6 MeV mono-energetic photon
induced reaction on natC using laser electron photon beam at NewSUBARU"
T. Itoga, H. Nakashima, T. Sanami, Y. Namito, Y. Kirihara, S. Miyamoto, A. Takemoto, M.Yamaguchi
and Y. Asano
EPJ Web of Conferences 153, 07010 (2017). DOI: 10.1051/epjconf/201715307010

5.

"Partial photoneutron cross section measurements on 209Bi"
I. Gheorghe, D. Filipescu, S. Katayama, H. Utsunomiya, S. Belyshev, K. Stopani, V. Varlamov, T. Shima,
Y.-W. Lui, S. Amano, and S. Miyamoto
EPJ Web of Conferences 146, 05011 (2017).

6.

"Photoneutron Reaction Data for Nuclear Physics and Astrophysics"
H. Utsunomiya, T. Renstrøm, G. M. Tveten, I. Gheorghe, D. M. Filipescu, S. Belyshev, K. Stopani, H.
Wang, G. Fan, Y.-W. Lui, D. Symochko, S. Goriely, A.-C. Larsen, S. Siem, V. Varlamov, B. Ishkhanov, T.
Glodariu, M. Krzysiek, D. Takenaka, T.Ari-izumi, S. Amano1, S. Miyamoto
Proceedings of the CGS16 Conference (Shanghai, September 2017).

7.

"Erosion process of fluorinated diamond-like carbon films by exposure to soft X-rays"
Kazuhiro Kanda, Hiroki Takamatsu, Eri Miura-Fujiwara, Hiroki Akasaka, Akihiro Saiga, Koji Tamada,
Masahito Tagawa, Kumiko Yokota, and Yuichi Furuyama (invited)
The Collaborative Conference on Materials Research (CCMR), Jeju, South Korea, Jun. 26-30 (2017).

8.

"Classification of Hydrogen-Free and Hydrogenated DLC Films Prepared by Filtered Arc
Deposition"
Toru Harigai, Takahiro Imai, Yoshiyuki Suda, Hirofumi Takikawa, Masao Kamiya, Satoru Kaneko,
Shinsuke Kunitsugu, Masahito Niibe, and Kazuhiro Kanda
IUMRS-ICAM 2017, Kyoto, Japan Aug. 27-Sep. 1 (2017).

9.

"DLC denture coating and the effect of prevention of contamination in oral cavity"
Yuichi Imai, Kazuhiro Kanda, Yoko Kato, Teppei Horikawa, and Tatsuyuki Nakatani
Plasma Conference 2017, Himeji, Japan, Nov. 20-24 (2017).

10. "Observation of B-K Emission and Absorption Spectra of Trace Boron Doped in HOPG"

185

Masahito Niibe, Noritaka Takehira and Takashi Tokushima
The 8th International Symposium on Surface Science (ISSS-8), Tsukuba, Oct. 2017.
11. "Surface Structure Analysis of AlGaN Thin Films Damaged by Oxygen and Nitrogen Plasmas"
Masahito Niibe, Ryo Tanaka, Retsuo Kawakami, Yoshitaka Nakano and Takashi Mukai
The 8th International Symposium on Surface Science (ISSS-8), Tsukuba, Oct. 2017.
12. "Generation Behavior of Electrical Damage Introduced into n-GaN Films by CF4 Plasma
Treatments"
Yoshitaka Nakano, Retsuo Kawakami and Masahito Niibe
29th International Conf. on Defects in Semiconductors (ICDS), Matsue, Aug. 2017.
13. "TiO2 Thin Film Surfaces Treated by O2 Plasma in Dielectric Barrier Discharge with Assistance ofHeat Treatment"
Retsuo Kawakami, Kengo Fujimoto, Masahito Niibe, Yuma Araki, Yoshitaka Nakano and Takashi Mukai
Proc. 14th International Symp. Sputtering & Plasma Processes, 274-277, Kanazawa, Jul. 2017.
14. "Laser Plasma soft X-ray Source Based on Cryogenic Target"
S. Amano (Invited)
SPIE, Optics+Optoelectronics, Prague, Czech Republic, April 24-27, 2017.
15. "Surface morphology changes of CVD-graphene/Cu{120} induced by post-annealing processes"
Y. Ogawa, Y. Murata, S. Suzuki, H. Hibino, S. Heun, K. Kumakura
30th Int. Microprocess and Nanotechnology Conf. (MNC2017), Jeju, Korea, November 7 (2017).
16. "Evolution of graphene alignment on recrystallizing polycrystalline Cu-foil for chemical vapor
deposition growth"
Yui Ogawa, Satoru Suzuki, Hiroki Hibino, Kazuhide Kumakura, Yoshitaka Taniyasu
Int. Symp. on Nanoscale Transport and Photonics 2017, Atsugi, November 14 (2017).
17. "T Molecular orientation of photoreactive liquid crystalline polymer films observed by NEXAFS"
Y. Haruyama, M. Okada, E. Nishioka, M. Kondo, N. Kawatsuki, and S. Matsui
European Congress and Exhibition on Advanced Materials and Processes (EUROMAT2017),
Thessaloniki, Greece, 2017/9/19
18. "CESIUM ION DOPED NICKEL OXIDE LAYERS FOR INVERTED PEROVSKITE SOLARCELLS"
Shota Fukumoto, Naoyuki Shibayama, Hiroyuki Kanda, Ajay Kumar Baranwal, Yuichi Haruyama,
Hiroshi Segawa, Tsutomu Miyasaka, Seigo Ito
The 27th International Photovoltaic Science and Engineering Conference (PVSEC-27), Otsu, Japan
2017/11/14
19. "Development of EUV Phase Imaging Microscope for Mask-3DEffect and Defect Evaluation"
Tetsuo Harada, Daiki Mamezaki, and Takeo Watanabe
Photomask Japan, Yokohama, April 5 - 7, 2017.
20. "NewSUBARU EUVL R&D Activities and EUV Mask Defect Inspection (Invited talk) "Takeo Watanabe, Tetsuo HaradaInternational Workshop on EUV Lithography, San Francisco, CA, USA, Jun. 12- 15, 2017.
21. "Resist Investigation Method using ab initio MO Calculation on basis of Approximation Molecular286Model"S. Nagata, S. Niihara, T. Harada, and T. Watanabe,
The 34th International Conference of Photopolymer Science and Technology
Makuhari Messe, Chiba, Japan, Jun. 26-29, 2017.
22. "Absorption Coefficient Measurement Advanced Method of EUV Resist by Direct-Resist Coating
on a Photodiode"
Shota Niihara, Daiki Mamezaki, Masanori Watanabe, Tetsuo Harada, Takeo Watanabe
The 34th International Conference of Photopolymer Science and Technology
Makuhari Messe, Chiba, Japan, Jun. 26-29, 2017.
23. "Evaluation of Block Copolymer Structure using Soft X-ray Scattering"
Yusuke Nakatani, Tetsuo Harada, Atsushi Takano, Motoyuki Yamada, Takeo Watanabe
The 34th International Conference of Photopolymer Science and Technology
Makuhari Messe, Chiba, Japan, Jun. 26-29, 2017.
24. "EUV Lithography Research and Development Activities at University of Hyogo (Invited talk) "Takeo Watanabe
OSA Laser Congress 2017, Nagoya Congress Center, Oct.,.1-5, 2017.
25. "Current Status and Prospect for EUV lithography (Panelist) "Takeo Watanabe
OSA Laser Congress 2017, Nagoya Congress Center, Oct.,.1-5, 2017.
26. "EUV Lithography Research and Development Activities at University of Hyogo"
Takeo Watanabe
IMEC meeting, Leuven, Belgium, Oct. 13, 2017.
27. "Current Status and Prospect for EUV lithography (Plenary talk) "Takeo Watanabe
2017 7th International Conference on Integrated Circuits, Design, and Verification (ICDV2017), Hanoi,
Vietnam, Oct. 5-6, 2017.
28. "Observation of EUVL Mask Using Coherent EUV Scatterometry Microscope with
High-Harmonic-Generation EUV Source"
Daiki Mamezaki, Tetsuo Harada, and Takeo Watanabe
Photomask Japan, Yokohama, April 5-7, 2017.
29. "Development of Polarization Control Unit with Broadband Mo/Si Multilayer for Accurate EUV
Reflectometry"
Masanori Watanabe, Tetsuo Harada, and Takeo Watanabe
Photomask Japan, Yokohama, April 5-7, 2017.
30. "Large Collector Mirror Reflectometer for the High Power EUV Light Source Achievement"
Takeo Watanabe and Tetsuo Harada Takeo Watanabe, Tetsuo Harada,2017 International Workshop on EUV Lithography, San Francisco, CA, USA, Jun. 12- 15, 2017.
31. "EUV Lithography Research and Development Activities at University of Hyogo"
Takeo Watanabe and Tetsuo Harada
2017 International Workshop on EUV Lithography, San Francisco, CA, USA, Jun. 12- 15, 2017.

38732. "EUV resist development at NewSUBARU in University of Hyogo"
Takeo Watanabe, Shota Niihara, Shohei Nagata, Masahiro Watanabe, Daiki Memezaki, Tetsuo Harada
Photomask Technology + Extreme Ultraviolet Lithography 2017, Monterey, CA, USA, 2017.9.11-14.
33. "A Study of EUV Resist Sensitivity by using metal materials"
Atsushi Sekiguchi, Yoko Matsumoto, Yoshiyuki Utsumi, Michiya Naito, Takeo Watanabe and Tetsuo
HaradaPhotomask Technology + Extreme Ultraviolet Lithography 2017, Monterey, CA, USA, 2017.9.11-14.
34. "Development of the negative-tone molecular resists for EB/EUVL having high EUV absorption
capacity, and molecular design method"
Takashi Sato, Tomoaki Takigawa, Yuta Togashi, Takumi Toida, Masatoshi Echigo, Tetsuo Harada, Takeo
Watanabe, Hiroto Kudo
Photomask Technology + Extreme Ultraviolet Lithography 2017, Monterey, CA, USA, 2017.9.11-14.
35. "Development of EUV phase imaging microscope for mask-3D-effect and defect evaluation"
Tetsuo Harada, Daiki Mamezaki, Yusuke Nakatani, Takeo Watanabe
Photomask Technology + Extreme Ultraviolet Lithography 2017, Monterey, CA, USA, 2017.9.11-14.
36. "Caltrop cupric oxide particles synthesized by X-ray photochemical reaction"
A. Yamaguchi, I. Okada, T. Fukuoka, and Y. Utsumi2017 International Conference on Electronics
Packaging (ICEP 2017), Yamagata, Japan, 2017/4/20
37. "Control of domain structure in artificial Ni wires fabricated on a LiNbO3 substrate"
A. Yamaguchi, T. Ohkochi, A. Yasui, T. Kinoshita, K. YamadaIntermag 2017, Dublin, Ireland, 24th-28th, April, 201738. "Dielectrophoresis-enabling Dynamic Formation of Higher-Order Nanostructure Consisting of
Au-nanoparticles-Decorated Polystyrene Beads for SERS Detection"
A. Yamaguchi, T. Fukuoka, Y. Utsumi
The 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS
2017), Savannah, USA, 22nd-26th, Oct., 201739. "Strain-induced magnetic properties of micro-scale artificial magnets on ferroelectric LiNbO3
substrate"
A. Yamaguchi, K. Ueda, T. Nakajima, Y. Utsumi, T. Ohkochi, A. Yasui, T. Kinoshita, K. Yamada
The 62nd Annual Conference on Magnetism and Magnetic Materials (2017 MMM), Pittsburgh, USA,
November 6th-10th, 201740. "Ferromagnetic resonance of Ni wires fabricated on ferroelectric LiNbO3 substrate for studying
strain-induced magnetic properties"
A. Yamaguchi, K. Ueda, T. Nakajima, Y. Utsumi, K. Yamada
The 62nd Annual Conference on Magnetism and Magnetic Materials (2017 MMM), Pittsburgh, USA,
November 6th-10th, 201741. "Plasmonic Nanobeacon Based on Gold Nanoparticle Self-assembly for Universal
Bio-Nanosensing"
T. Fukuoka, A. Yamaguchi, Y. Mori
The first International Workshop by the 174th Committee JSPS“Symbiosis of Biology and Nanodevices”（第 174 委員会主催国際ワークショップ「Symbiosis of Biology and Nanodevices」）, Kyoto, Dec. 21st,
2017

4

88

(3) Academic degrees
1. Doctor of Engineering
Chiwa Kataoka (University of Hyogo)
作付け前診断のための土壌残留ヘプタクロル類の免疫学的測定法の構築と Lab-on-a-CD への応用に関する研究"Construction of immunoassay of heptachlor as a soil residue for diagnosis before cropping and its application
to Lab-on-a-CD"
2. Master of Engineering
Kento Sugita (University of Hyogo)
レーザーコンプトン散乱ガンマ線の発生と陽電子非破壊検査システムの開発"Development of Positron Non-destructive Inspection System Using Laser Compton Scattering Gamma-ray"
Shohei Nagata (University of Hyogo)
分子軌道計算法を用いた軟 X 線吸収分光測定によるレジスト評価手法の検討"EUV Resist Evaluation Using Soft X-Ray Absorption Spectroscopy and Molecular Orbital Calculation"
Yusuke Nakatani (University of Hyogo)
有機材料化学状態分布評価用の軟 X 線透過顕微鏡および共鳴散乱測定手法の開発"Developments of Scanning Transition Soft X-ray Microscope and Resonant Soft X-ray Scattering Method forDistribution Evaluation of Chemical State in Polymers"
Masanori Watanabe (University of Hyogo)
EUV リソグラフィ用多層膜の高精度反射率測定法の開発、並びにカシミール力測定用のピットパタ
ン製作"Development of Accurate Reflectometry of EUV Multilayer for EUV lithography, and Pit Pattern Fabrication
for Cacimir-Force Evaluation"
Daiki Mamezaki (University of Hyogo)
EUV マスクパタン像観察のための高次高調波回折顕微鏡の開発"Development of Standalone Diffraction Microscope with High-Harmonic-Generation EUV Coherent Source
for EUV Mask-Pattern Observation"

1
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LASTI Annual Report Vol.19 (2017)________________________________________________________
September 2018, Published byLaboratory of Advanced Science and Technology for Industry
University of Hyogo
3-1-2 Kouto, Kamigori-Cho, Ako-gun, Hyogo 678-1205, JAPAN
Phone: +81-791-58-0249 / FAX: +81-791-58-0242
Editorial board
Kazuhiro KANDA (Editor in Chief)
NIIBE Masahito
SHOJI Yoshihiko
HARUYAMA Yuichi
YAMAGUCHI Akinobu
HARADA Tetsuo______________________________________________________________