bluuebunny/crossref_metadata_2025 huggingface dataset:
High Data-Rate Phase-Change Media for the Digital Video Recording System
Authors: Tieke Benno , Dekker Martijn , Pfeffer Nicola , van Woudenberg Roel , Zhou Guo-Fu , Ubbens Igolt P. D.
Published: October 2002

The digital video recording (DVR) system combines a high numerical aperture (NA=0.85) with a thin cover layer to
achieve higher storage capacities in optical recording. In addition to capacity, the data-rate is a key parameter for DVR
and a major challenge in research on phase-change materials. Using Ge2Sb2Te5 as the phase-change material, we
demonstrate recording using a red laser diode (λ=650 nm) at a user data-rate of 33 Mbps and a capacity of 9.2 GB for a
single layer disc of 12 cm diameter, i.e. completely satisfying all the DVR system requirements. In addition, we
achieved data-rates of up to 50 Mbps by applying a different stack design. Furthermore, we extend DVR to the blue-violet wavelength region. Using a GaN laser diode (λ=400 nm) in our recording set up, a capacity of 21.5 GB was
achieved at a data-rate of 28 Mbps.
Overview and the Future of Phase-Change Optical Disk Technology
Authors: Ohta Takeo , Nishiuchi Kenichi , Narumi Kenji , Kitaoka Yasuo , Ishibashi Hiromichi , Yamada Noboru , Kozaki Takashi
Published: October 2002

Phase-change optical disk technology in the early days dealt with three issues: cyclability,
erase characteristics and sensitivity. These were resolved by materials development, and disk layer
structure technologies. This paper shows the high (carrier to noise ratio) C/N recording
characteristics of a multi-level phase-change optical disk. Multi-level mark radial width modulation
(MRWM) recording experiments have demonstrated 4-level (level 0, level 1, level 2 and level 3)
recording capability. Even level 1 marks with a radial width of 200 nm have a high C/N ratio of more
than 50 dB. The laser pulse width and laser power assigned MRWM, M-level recording is expected
the potential for marks storing density proportionally to log
2
M. This technology offers the feature of
enhanced density and compatibility with a digital versatile disk (DVD) pick-up.
Using Tungsten Oxide Based Thin Films for Optical Memory and the Effects of Using IR Combined with Blue/Blue-Green Wavelengths
Authors: Bussjager Rebecca , Chaiken Joseph , Getbehead Mark , Grucza David , Hinkel Captain Dan , McEwen Thomas , Osman Joseph , Voss Ethan
Published: October 2002

Utilizing a form of tungsten oxide as the physical medium for
optical memory, we show that infrared irradiation provides heat to
the lattice structure while blue or blue-green light provides
electronic excitation to initiate a photochromic chemical change. We
have constructed and tested a spin stand based demonstration system
for this form of optical memory. Tungsten oxide offers potential
advantages in storage density, storage capacity, write speed, signal
to noise, processing flexibility, data robustness, and overall, cost.
Exposure Method Using Photoresist Mask for High-Density Optical Disk Mastering
Authors: Shimizu Akihiko , Endo Hideyasu , Watanabe Hisao , Obara Takashi , Miyata Hiroyuki , Mizuta Osamu , Takeuchi Koji , Kudo Yuzuru , Hashiguchi Tsuyoshi
Published: October 2002

A high-density digital versatile disk (HD-DVD) is being
developed, aiming for high definition television. It is thought that
the capacity of HD-DVD would be 15 GB, for example when its track
pitch is 0.42 µm, its minimum mark length must be 0.22 µm. To
fabricate such a high-density optical disk, we develop an exposure
method using a photoresist mask. Super-resolution is also studied in
order to make the exposure beam diameter smaller.
Electronic Crosstalk Cancellation with a Quadrant Cell Detector
Authors: Upton Robert S. , Akhavan Farhad , Milster Tom D. , Schweisguth Michael , Bletscher Warren L. , Erwin J. Kevin , Nichol Anson M.
Published: October 2002

Single beam electronic crosstalk cancellation by a quadrant
cell detector placed in the exit pupil of an optical data storage
system is experimentally shown to reduce crosstalk levels by -10 dB and improve jitter by a factor of 2.5 for double density
recorded compact disk rewritable media (CD-RW). Simulations show
-21 dB reduction in crosstalk levels for CD-RW.
High Frequency Wobbles: A Write Clock Generation Method for Rewritable Digital Versatile Disk (DVD) That Enables Near Drop-In Compatibility with DVD-Read Only Memories (DVD-ROMs)
Authors: Abramovitch Daniel , Towner David , Perlov Craig , Hogan Josh , Fischer Michael , Wilson Carol , Ilkan Çokgör Ilkan Çokgör , Carl Taussig Carl Taussig
Published: October 2002

This paper describes a write clock generation scheme for rewritable digital versatile disk (DVD) which
eliminates a major issue for drop-in compatibility with DVD-read only memories (DVD-ROMs).
The method used is to co-locate a high frequency clock reference next to the
data using a wobble groove. This enables bit
accurate edits on rewritable DVD media.
Three-Dimensional Thermal Modelling and Analysis of Near-Field Phase Change Optical Disks
Authors: Ho Jia Jun , Lee Jek Chong , Chong Tow Chong , Shi Luping
Published: October 2002

Three-dimensional thermal finite-element modelling and analyses based on an
improved thermal model are performed on grooved near-field re-writable phase
change optical disk for the first time. The improved model takes into
consideration
the thermal effects generated by both the incident and reflected
light. Performance of
the disk as a result of optical and geometrical variations was
quantified. The thermal
effects due to irradiation by a 430 nm blue laser were also
investigated. Temperature
profiles and heat flow characteristics were obtained and analysed. One
set of result
obtained indicated that a numerical aperture of 1.5 with a coupling
efficiency of 50%
resulted in the highest recorded temperature.
Slope Nucleation Method for the Growth of High-Quality 4-Dimethylamino-Methyl-4-Stilbazolium-Tosylate (DAST) Crystals
Authors: Mori Yusuke , Takahashi Yoshinori , Iwai Takashi , Yoshimura Masashi , Yap Yoke Khin , Sasaki Takatomo
Published: October 2002

We have developed a new technique called the slope nucleation method (SNM) for the growth of high-quality 4-dimethylamino-methyl-4-stilbazolium-tosylate (DAST) crystals. This technique combines the spontaneous nucleation and subsequent growth of a single crystal into one process. The SNM features the ability to control the nucleation position and the growth orientation of DAST crystals. Many single crystals can be grown simultaneously in one process. X-ray diffraction (XRD) indicates that the SNM is effective for growing higher-quality DAST crystals as compared to conventional spontaneous nucleation and the top-seeded solution growth technique. DAST crystals with an XRD rocking curve as narrow as 20.2 arcsec full-width at half maximum (FWHM) were obtained.
Room-Temperature Electroluminescence from Metal-Oxide-Silicon-Tunneling Diodes on (110) Substrates
Authors: Liu Chee-Wee , Lee Min-Hung , Chang Shu-Tong , Chen Miin-Jang , Lin Ching-Fuh
Published: October 2002

We report the band-edge electroluminescence at room temperature from metal-oxide-silicon tunneling diodes on (110) substrates. An electron-hole plasma recombination model can be used to fit the emission line shape. The reliability of this electroluminescence is studied and the emission intensity varies within 10% during a 2.5×104 C/cm2 stress. A comprehensive illustration composed of localized holes, phonons, and interface roughness is given to describe the radiative process. The picture can be used to explain the enhanced electroluminescence intensity, as compared to photoluminescence, and can be used to understand the substrate orientation effect on electroluminescence intensity.
Effect of Conformations of Trans- and Cis-Azobenzenes on Photoinduced Anchoring Transitions in a Nematic Liquid Crystal
Authors: Ruslim Christian , Komitov Lachezar , Matsuzawa Yoko , Ichimura Kunihiro
Published: October 2002

Two azobenzenes with different positional substituents,
3,3′-dihexyloxy-2,2′-dimethylazobenzene
(3,3′-azo) and 4,4′-dihexyloxy azobenzene
(4,4′-azo), were doped onto a nematic liquid crystal (LC) to
form photoresponsive guest-host LC mixtures. The photoinduced
anchoring transition of the LC, triggered by trans-cis
photoisomerization of the two dyes subjected to linearly polarized UV
light was found to be different. Whereas the photoisomerization of
3,3′-azo only induced a transition from random planar (RP)
to uniform planar (UP) (in-plane) alignment, that of
4,4′-azo additionally induced a transition from uniform
planar to homeotropic (H) (out-of-plane) alignment of the LC at a
longer exposure time. The anchoring behavior of the two azobenzenes is
discussed in terms of the conformations of their trans- and
cis-isomers and the interactions of the isomers with the
solid surface of the substrate.
One-Step Synthesis for Zn2SiO4:Mn Particles 0.3–1.3 µm in Size with Spherical Morphology and Non-Aggregation
Authors: Lenggoro I. Wuled , Iskandar Ferry , Mizushima Hiroaki , Xia Bin , Okuyama Kikuo , Kijima Naoto
Published: October 2002

Particles of the green luminescent Zn2SiO4:Mn having size of 0.3–1.3 µm was directly prepared by spray pyrolysis without post-annealing processes. Characteristics of as-prepared particles such as crystallinity, morphology, and photoluminescence were investigated. Zn2SiO4:Mn particles with spherical morphology, non-aggregation, and having pure willemite was formed at a temperature of 1000–1300°C. The luminescence of the Mn2+ ion in Zn2SiO4 shows an emission band in the 525 nm when excited by 254 nm light.
Epitaxial Growth of Si1-yCy Film by Low Temperature Chemical Vapor Deposition
Authors: Syuhei Yagi Syuhei Yagi , Katsuya Abe Katsuya Abe , Akira Yamada Akira Yamada , Makoto Konagai Makoto Konagai
Published: October 2002

Epitaxial Si1-y
Cy films were grown on Si(100) by two methods, mercury sensitized photochemical vapor deposition and plasma-enhanced chemical vapor deposition, at substrate temperatures of around 200°C using SiH4, H2 and C2H2. The vibration mode at 607 cm-1, which indicated the presence of the C atoms located at the Si substitutional sites, was observed in both Fourier transform infrared absorption and Raman scattering spectroscopy of the samples annealed at 600 to 700°C. The C composition was controlled by varying the C2H2/SiH4 ratio. The maximum substitutional C compositions of 2.3 at% and 2.7 at% were successfully obtained by mercury sensitized photochemical vapor deposition and plasma-enhanced chemical vapor deposition, respectively.
Proton Acceleration in Transverse Laser Wake Fields
Authors: Mohammad Bakhtiari Mohammad Bakhtiari , Hiroaki Ito Hiroaki Ito , Masashi Imai Masashi Imai , Noboru Yugami Noboru Yugami , Yasushi Nishida Yasushi Nishida
Published: October 2002

The possibility of accelerating protons by wake fields excited by ultrashort high-power lasers is discussed. The acceleration condition and energy gain of a proton injected in a transverse component of a laser wake field is investigated. The energy gain strongly depends on the initial phase to the laser wake field when protons are injected inside the field.
Effect of Low-Energy Ion Bombardment upon Field-Stimulated Exoelectron Emission from Tungsten Surfaces
Authors: Tadashi Shiota Tadashi Shiota , Sinji Kibi Sinji Kibi , Ryo Yamamoto Ryo Yamamoto , Masahito Tagawa Masahito Tagawa , Nobuo Ohmae Nobuo Ohmae , Masataka Umeno Masataka Umeno
Published: October 2002

The field-stimulated exoelectron emission (FSEE) from a tungsten surface
bombarded by helium ions with incident energies ranging from 300 to 580 eV
was investigated. When a tip was cooled down to 185 K, FSEE was clearly
detected at the ion-bombarded tungsten surface with incident energies higher
than 500 eV which corresponds to the sputtering threshold of tungsten atoms.
A decay of FSEE intensity was also observed after the ion bombardment. In
contrast, FSEE was not obvious at the tip temperature of 300 K. These
experimental results would be explained by the emission model which is
related to a rearrangement of surface tungsten atoms distorted by the ion
bombardment.
Atomic Short-Range Order in an Al72Ni20Co8 Decagonal Quasicrystal by Anomalous-X-Ray Scattering
Authors: Abe Hiroshi , Matsuo Yoshie , Saitoh Hiroyuki , Kusawake Tomoko , Ohshima Ken-ichi , Nakao Hironori
Published: October 2002

By anomalous-X-ray scattering, the diffuse scattering around Bragg reflections was observed in a single decagonal quasicrystal of Al72Ni20Co8, which has no phason strain. The diffuse scattering is distributed around the center of the superstructure points. Intensity modulations of the diffuse scattering occur at each incident wavelength. The contrast of diffuse scattering shows the presence of atomic short-range order (SRO) in three kinds of pair correlation functions: between Al and Ni, between Ni and Co and between Co and Al. The correlation length of the diffuse scattering is estimated to be 22.5 Å.
Analysis of Current Components Observed by Cyclic Current–Voltage Measurement in Metal-Oxide-Semiconductor Capacitors
Authors: Hyungoo Jeon Hyungoo Jeon , Sungwoo Choi Sungwoo Choi , Byungchul Ahn Byungchul Ahn , Yonghan Roh Yonghan Roh
Published: October 2002

We have used the cyclic current–voltage (I–V) technique to characterize border traps generated by Fowler-Nordheim tunnel (FNT) electron injection in metal-oxide-semiconductor (MOS) capacitors. We clarified that the current components measured from as-grown samples by the cyclic I–V technique are directly related to the formation or removal of an inversion layer, and we refer to such data as the background current. On the contrary, the distinct peaks in the I–V curves were developed in addition to the background current after generating border traps by FNT electron injection. We suggest that the peaks were caused by the reversible charge-exchange between border traps and underlying Si via donor-like interface traps located near the 0.35 eV above the valence band edge.
Electrochemical Method for Evaluation of Structural Perfection of Hydrogen-Terminated Si(111) Surface
Authors: Bensliman Fahd , Aggour Mohammed , Ennaoui Ahmed , Matsumura Michio
Published: October 2002

In this study, we measured the electrochemical oxidation currents on n-Si(111) surfaces at a potential near the flat-band potential. The current became small when the surface was treated with oxygen-free water, which is effective for flattening the Si(111) surface, before the electrochemical measurement. This current was attributed to the oxidation of Si atoms on step and kink sites, and was concluded to be a good measure of the structural perfection of Si(111) surfaces.
Growth of Y-Ca-Ba-La-Cu-O Tetragonal Superconductors by Liquid-Phase Epitaxy
Authors: Kita Ryusuke , Ishibe Yasuhisa , Suzuki Tomoki
Published: October 2002

Thick films with a tetragonal structure were grown on NdGaO3 (110) substrates by the liquid-phase epitaxy technique using a mixture of Y0.4Ca0.6Ba1.4La0.6Cu3O
x
and BaCuO2–CuO flux. The Ca and La concentrations in the films were found to be about 1/9 and 1/2 of those in the solute, respectively. The films showed a sharp superconducting transition with T
c(zero)=79.4 K and a transition width of 0.8 K. The growth of the films changed from a c-axis orientation to an a-axis orientation with an increase in the growth temperature and the holding time of the molten solution.
Optical and Structural Studies of Proton-Exchanged Waveguides in Z-Cut LiTaO3
Authors: Hui Hu Hui Hu , Fei Lu Fei Lu , Feng Chen Feng Chen , Ji-Tian Liu Ji-Tian Liu , Jian-Hua Zhang Jian-Hua Zhang , Ke-Ming Wang Ke-Ming Wang , Bo-Rong Shi Bo-Rong Shi
Published: October 2002

Waveguide modes and interference phenomenon were observed using the prism couple technique in the proton-exchanged LiTaO3 waveguides. The loss of the LiTaO3 waveguide was measured by the fiber probe technique. A low loss (0.7 dB/cm) optical waveguide was obtained. The disorder of the Ta atoms in the proton-exchanged layers was detected by Rutherford backscattering/channeling technique.
Electrical Conductivity of Carbon Pellets from Mixtures of Pyropolymer from Oil Palm Bunch and Cotton Cellulose
Authors: Deraman Mohamad , Zakaria Sarani , Omar Ramli , Aziz Astimar A.
Published: October 2002

Self-adhesive carbon grains (sacg1) and heat-treated kraft lignin (htkl) were prepared from the oil palm empty fruit bunch, a potential precursor for carbon products due to its large availability from palm oil mills, and sacg was prepared from cellulose (sacg2). Pellets were prepared from mixtures of sacg1 and htkl, as well as sacg1 and sacg2, with varying percentages of htkl (P
htkl%) and sacg2 (P
sacg2%). After carbonization up to 1000°C, the measured electrical conductivities, σ (Ω·cm)-1, of the respective pellets follow the equations σ=4.13P
htkl+2.43 and σ=0.53P
sacg2+2.55, respectively, indicating that htkl has improved in its conducting phase compared to sacg2.
Generation of Pretilt Angle and Liquid Crystal Aligning Capabilities Using a Photodimerization Method on a Photo-Polymer Surface
Authors: Seo Dae-Shik , Hwang Jeoung-Yeon
Published: October 2002

Pretilt angles and alignment stability for nematic liquid crystal (NLC) with obliquely polarized UV exposure on the three kinds of photo-polymer were studied. The generated pretilt angle of the NLC was about 2.7° by polarized UV exposure on a PM4Ch (poly(4-methacryloyloxy chalcone)) surface for 1 min. But, the low pretilt angle for NLC on a PVCi (poly(vinyl)cinnamate) surface was observed. The pretilt angle generated in NLC is attributed to the photosensitivity by long side chain of the photo-polymer. Also, good thermal stability of the three kinds of photo-polymer were measured until 300°C by thermogravimetric analysis (TGA) measurement. Finally, the good LC aligning capabilities using the photodimerization method were observed by annealing-treatment until 150°C.
Wavelength-Dispersive Total Reflection X-Ray Fluorescence with High-Brilliance Undulator Radiation at SPring-8
Authors: Awaji Naoki , Ozaki Shinji , Nishino Junichi , Noguchi Sinichi , Yamamoto Tohru , Syoji Takashi , Yamagami Motoyuki , Kobayashi Akira , Hirai You , Shibata Masahiro , Yamaguchi Koji , Liu Kuang-Yu , Kawado Seiji , Takahashi Mamoru , Yasuami Shigeru , Konomi Ichiro , Kimura Shigeru , Hirai Yasuharu , Hasegawa Masaki , Komiya Satoshi , Hirose Takayuki , Okajima Toshihiro
Published: October 2002

Wavelength-dispersive total reflection X-ray fluorescence (WD-TXRF) equipment supported by an energy-dispersive (ED) solid-state detector (SSD) has been developed and installed in the BL16XU Industrial Consortium ID Beamline for Material Research at the SPring-8 synchrotron radiation research facility. Equipment specifications are given and results from our initial experiment are discussed in this paper. In the experiment on the sensitivity of detection of metallic impurities on a Si wafer, the lower limit of detection (LLD) using a Ge-SSD reached an order of 108 atoms/cm2 with a corresponding absolute weight of approximately 10 fg for ED-TXRF. In comparison, an order of 109 atoms/cm2 with a corresponding weight of around 100 fg was obtained for WD-TXRF for the first time. Although ED-TXRF still has a lower LLD, using WD-TXRF can provide good energy resolution with a high count rate, opening up a new field of X-ray fluorescence measurement.
Observation of Triple-Period-A Type Atomic Ordering in Sb-Doped Ga0.5In0.5P Alloys
Authors: Ichihashi Toshinari , Kurihara Kaori , Nishi Kenichi , Suzuki Tohru
Published: October 2002

Triple-period-A (TP-A) type ordering of atoms has been observed
in Sb-doped Ga0.5In0.5P grown by metal-organic vapor-phase
epitaxy on (001)GaAs at ∼650°C. The appearance
of TP-A type ordering at such a high temperature with a very low
flow-rate for Sb is believed to result from the formation of
(2×3) surface reconstruction with double
Sb-rich-group-V-surface-layers during growth, due to the antimony's
low vapor pressure. Sb constituted as little as 1.6% of the atoms
in the group-V sublattice. A peculiar characteristic in the pattern
of the diffuse scattering from Sb-doped Ga0.5In0.5P was
interpreted to result from the novel orientation of the shallow
disk-shaped domains of TP-A type ordering.
Dual-Beam Trapping Method for an Object with Large Relative Refractive Index
Authors: Kozo Taguchi Kozo Taguchi , Masaru Tanaka Masaru Tanaka , Masahiro Ikeda Masahiro Ikeda
Published: October 2002

A novel dual-beam trapping method was proposed and discussed for the three-dimensional optical trapping of an object. We theoretically studied the optical forces on a sphere by the laser beams from plural optical fiber ends inserted into a sample cell at an angle. There was only one stable point of equilibrium located below the beam-crossing point and significantly enhanced stability was obtained. Furthermore, we revealed the feasibility of trapping an object with large relative refractive index.
Raman Analysis of Wurtzite Silicon Islands in Silicon Oxide Deposited in N2O–SiH4 Plasma Process
Authors: Bandet Jacqueline , Despax Bernard , Caumont Michael , Date Lucien
Published: October 2002

We report on the deposition of stable wurtzite Si islands
in a silicon oxide deposition process with N2O-Silane
plasma ([SiH4]<2%). They were brought to the fore by
Raman spectroscopy using a high resolution microprobe. By means of group
theory, we were able to discriminate among these clusters, wurtzite silicon,
diamond silicon and mixed crystals. We showed experimentally that they were the
result of dust formation in the N2O–SiH4 radiofrequency discharge.
Electrooptic Measurement in the Vicinity of SmA-SmCα
* Phase Transition of an Antiferroelectric Liquid Crystal
Authors: Andika Fajar Andika Fajar , Hiroshi Orihara Hiroshi Orihara , Valery Bourny Valery Bourny , Jiri Pavel Jiri Pavel , Vladimir Lorman Vladimir Lorman
Published: October 2002

Electrooptic measurements have been performed around the
SmA-SmCα
* phase transition point in an antiferroelectric liquid
crystal 4-(1-methyl-heptyloxycarbonyl)phenyl 4'-octyloxybiphenyl-4-carboxylate
(MHPOBC). The first-order electrooptic response was continuous with a
small slope change at the SmA to SmCα
* transition point in the
temperature dependence curve, while the second-order electrooptic response exhibited
an anomalous increase near the transition point. We present a simple theory
and demonstrate that this anomaly originates in the pretransitional fluctuations.
The frequency dispersion of the electrooptic response is also presented.
High-Rate Epitaxy of Anatase Films by Atmospheric Chemical Vapor Deposition
Authors: Shuji Tokita Shuji Tokita , Norio Tanaka Norio Tanaka , Hidetoshi Saitoh Hidetoshi Saitoh
Published: October 2002

Crystalline orientation often provides particularly the anisotropy
of chemical and physical properties.
Since the epitaxial films are composed of highly oriented crystals,
it is expected that chemical and physical advantages are
predominantly in one specific direction.
In this study, high-rate epitaxy of anatase films was attempted
using a chemical-vapor-deposition technique.
Four types of epitaxial anatase films were obtained,
i. e. , <112 >, <110>,
<100 > and <001 >
oriented normal to the substrate surface.
These films reduced methylene blue under ultraviolet irradiation.
The reduction rate of methylene blue was largely affected
in the direction of crystalline orientation.
Visible Laser Action of Dy3+ Ions in Monoclinic KY(WO 4) 2 and KGd(WO 4) 2 Crystals under Xe-Flashlamp Pumping
Authors: Tae Seo Alexander Kaminskii , Ken-ichi Ueda Ken-ichi Ueda , Sergey Bagayev Sergey Bagayev , Aleksey Pavlyulk Aleksey Pavlyulk
Published: October 2002

Pulsed laser action in the novel visible laser channels 4F9/2→6H13/2 (at ≈0.57 µm) and 4F9/2→6H11/2 (at ≈0.66 µm) of Dy3+ ions in monoclinic KY(WO4)2 and KGd(WO4)2 single crystals at nitrogen cryogenic temperature under Xe-flashlamp pumping is excited for the first time. All observed lasing emissions are identified. Some spectroscopic characteristics of the investigated crystals are also presented.
Diamond Film Gas Sensors for Leak Detection of Semiconductor Doping Gases
Authors: Hayashi Kazushi , Yokota Yoshihiro , Tachibana Takeshi , Miyata Koichi , Kobashi Koji , Fukunaga Tetsuya , Takada Tadashi
Published: October 2002

Gas sensors for leak detection of toxic semiconductor doping
gases such as PH3, B2H6, and AsH3 were fabricated
using diamond films. The sensors have a double-layered structure
composed of undoped and B-doped polycrystalline diamond layers with Pt
electrodes. The relative changes in the resistance of the sensors
were typically 10–20% for 0.2 ppm PH3 in air, and the highest
value was over 100%. It was concluded that the diamond film gas
sensors fabricated in the present work would be practically applicable
as compact solid-state sensors with an advantage over the conventional
aqueous electrolyte sensors.
Improvement of the Electrical Properties of β-FeSi 2 Films on Si (001) by High-Temperature Annealing
Authors: Ken-ichiro Takakura Ken-ichiro Takakura , Takashi Suemasu Takashi Suemasu , Noriyoshi Hiroi Noriyoshi Hiroi , Fumio Hasegawa Fumio Hasegawa
Published: October 2002

The crystal quality, mobility and carrier density of the continuous and [100]-oriented nondoped β-FeSi2 films prepared from Si/Fe multilayers on Si (001) substrates using templates were improved by high-temperature annealing, in particular, at 900°C. All the annealed samples exhibited n-type conduction. The maximum electron mobility of β-FeSi2 indicated 6900 cm2/V·s (46 K) after annealing at 900°C for 42 h. This mobility is about 15 times higher than that reported so far for nondoped n-type β-FeSi2. The electron density at room temperature decreased from 2×1020 cm-3 to
3×1018 cm-3 after the annealing.
Transport Parameters of Electron Swarms in SF6and Argon Gas Mixtures
Authors: Xiao Deng-Ming , Li Hong-Lei , Chen Ya-Zhu
Published: October 2002

The electron swarm growth processes in SF6-Ar gas mixtures have been studied by a pulsed Townsend method over the range 32.24≤E/N≤564.2 Td (1 Td=10-21V·m2), whereEis the electric field andNis the gas density of the mixture. The variation patterns as functions of the density-reduced electric field of the effective ionization coefficient α, electron drift velocityVeand longitudinal diffusion coefficientDLin SF6-Ar gas mixtures have been given. The dielectric strength of SF6-Ar gas mixtures has also been determined, and found to vary linearly with SF6concentration in the gas mixtures.
Effects of Hydrogenation and Annealing on the Deep Levels in GaN Epilayers Grown on Sapphire Substrates
Authors: Kang Tae Won , Yuldashev Shavkat U. , Kim Duek Young , Kim Tae Whan
Published: October 2002

The photoionization cross section and the concentration of state of the
deep levels in as-grown,
hydrogenated, and hydrogenated and annealed GaN epilayers were
determined from the dependence of the
rise and the decay times of the extrinsic photoconductivity (PC)
response on the post treatment condition.
The values of the concentrations of the deep levels in the GaN epilayer
decreased by the hydrogenation and
the annealing treatment. While the thermal activation energy of the deep
level, which were determined from
the temperature dependence of the relaxation times of the extrinsic PC
response, for the hydrogenated
GaN/sapphire heterostructure decreased in comparison with that for the
as-grown sample, that for the
hydrogenated and annealed sample increased in comparison with that for
the hydrogenated sample.
Erasing Mechanisms of Ag–In–Sb–Te Compact Disk (CD)-Rewritable
Authors: Chang Yem-Yeu , Chou Lih-Hsin
Published: October 2002

The erasing mechanisms of Ag–In–Sb–Te Compact Disk (CD)-Rewritable at CD
2X and CD 4X are studied by employing the transmission electron microscopy (TEM). The
mechanisms of laser-induced crystallization vary with linear velocity as well as erase
power. Under CD 2X recording, erasing is proceeded with nucleation and growth
mechanism at low erase laser power. However, it is the direct grain growth that
controls the mechanism of erasing at higher erase power. Under CD 4X recording, the
erasing is dominated by direct grain growth originated from the interface between
amorphous marks and their neighboring crystalline region, and the erase power
determines the location where the grain growth begins.
Anomalous Capacitance Bounces and Bumps of Liquid Crystal Cells in DC Electric Fields
Authors: Po-Lun Chen Po-Lun Chen , Shu-Hsia Chen Shu-Hsia Chen
Published: October 2002

We have studied the time response of the capacitance of nematic liquid crystal cells by applying electric fields. When AC fields are applied, the capacitance exhibited a normal behavior: it first increased monotonically with time, and then reached a saturating value. With sufficient high DC fields, capacitance bounces and bumps were observed during the rising time for 100-µm thick cells with low and high impurity concentrations, respectively. We believe that these anomalous capacitance characteristics of liquid crystal cells are resulted from the coupling effects between induced polarization from liquid crystal molecules and space-charge polarization from fast ions.
Valence Band and Bandgap States of Ferroelectric SrBi2Ta2O9 Thin Films
Authors: Watanabe Koji , Hartmann Andreas J. , Lamb Robert N. , Craig Richard P. , Thurgate Steve M. , Scott James F.
Published: October 2002

Ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy
(XPS) and surface photovoltage spectroscopy (SPV) were used to determine the
electronic structure near the bandgap of strontium bismuth tantalate (SBT) thin films.
The UPS results for nearly stoichiometric SBT have been compared with tight-binding
calculations. The spectra for bismuth-excess SBT indicate additional density of states
(DOS) in the wide bandgap of the material. SPV studies indicate that the surface
bandgap of bismuth-excess SBT is approximately 2 eV, which also confirms that there
are additional surface states in the bandgap. These electronic structural data are used
to explain the observed dependency of the electrical properties of the SBT/electrode
junction on the bismuth concentration.
Two-Dimensional Hydrogen Analysis of Hydrogen Storage Alloy Surface by Electron-Stimulated Desorption Microscopy
Authors: Ueda Kazuyuki , Ishikawa Ken'ichi , Ogai Keiko , Yoshimura Masamichi
Published: October 2002

Hydrogen analysis on the solid surfaces in an ultrahigh vacuum has been
performed by electron stimulated desorption (ESD) microscopy. A scanning
time-of-flight (TOF)-ESD measured a two-dimensional hydrogen distribution with a
spatial resolution of less than 1 µm. Scanning TOF-ESD was applied to a hydrogen
storage alloy surface (vanadium-titanium-nickel system) in order to measure the
two-dimensional distribution of hydrogen. In the clear image, hydrogen is distributed
mainly on the matrix of the vanadium surface and oxide layers localize on the titanium
and nickel at grain boundaries.
Flow-Rate Modulation Epitaxial Growth of Zn1-yMgySxSe1-x on GaAs
Authors: Lee Ming-Kwei , Pan Shyi-Shuh , Tsay Bor-Tzong
Published: October 2002

The quaternary Zn1-y
Mg
y
S
x
Se1-x
epilayers were grown on GaAs by low-pressure flow-rate modulation organometallic vapor phase epitaxy. We find that not only biscyclopentadienyl-magnesium (CP2Mg) but also diethylzinc (DEZn) react with H2S in the gas-phase of low-pressure organometallic vapor phase epitaxy from secondary ion mass spectroscopy (SIMS) observation. The magnesium content y and the sulfur content x in the quaternary Zn1-y
Mg
y
S
x
Se1-x
alloys cannot be controlled independently. The flow-rate modulation epitaxy can reduce the prereactions and improve the quality of the epitaxial growth of the quaternary Zn1-y
Mg
y
S
x
Se1-x
alloys.
Physical Properties of Polar Bis-Tolane Liquid Crystals
Authors: Wu Shin-Tson , Hsu Chain-Shu , Chuang Ya-Yun , Cheng Han-Bin
Published: October 2002

Several cyano and fluoro bis-tolane liquid crystals were synthesized and their physical
properties evaluated. Some of these highly conjugated liquid crystals possess birefringence larger
than 0.5 in the visible region. Adding 10% of a binary bis-tolane mixture to a cholesteric display
enhances the brightness by more than 20%.
High-Rate Deposition of High-Quality, Thick Cubic Boron Nitride Films by Bias-Assisted DC Jet Plasma Chemical Vapor Deposition
Authors: Matsumoto Seiichiro , Zhang Wenjun
Published: October 2002

Cubic boron nitride thin films were deposited on (100) silicon substrates by DC jet plasma chemical vapor deposition in an Ar–N2–BF3–H2 gas system. Negative DC bias was applied on the substrate during deposition. Scanning electron microscopy, x-ray diffraction, infrared and Raman spectroscopy were carried out to characterize the samples. It was found that boron nitride films with cubic phase over 90% were synthesized under optimized conditions. A high deposition rate of about 0.3 µm/min and a film thickness over 3 µm were firstly achieved. Furthermore, the Raman measurements show clear TO and LO characteristic peaks of c-BN with a full width at half maximum of 28.8 and 19.7 cm-1, revealing a high quality of the deposited films.
High-Pulse-Energy Ultraviolet Ce3+:LiCaAlF6 Laser Oscillator with Newly Designed Pumping Schemes
Authors: Liu Zhenlin , Shimamura Kiyoshi , Nakano Kenji , Fukuda Tsuguo , Kozeki Toshimasa , Ohtake Hideyuki , Sarukura Nobuhiko
Published: October 2002

Using a large Ce3+:LiCaAlF6 (Ce:LiCAF) crystal, 60 mJ pulses
were generated directly from a quasi-coaxially pumped Ce:LiCAF
laser. In addition, a new noncollinear Brewster-angle-pumping disk
oscillator scheme was demonstrated for further output-energy scaling.
Tersoff Potential Parameters for Simulating Cubic Boron Carbonitrides
Authors: Matsunaga Katsuyuki , Fisher Craig , Matsubara Hideaki
Published: October 2002

We have developed Tersoff potential parameters for boron in
order to simulate cubic boron carbonitride systems by molecular
dynamics. Combined with parameters for C and N available from the
literature, our parameters are shown to reproduce the lattice
parameters and bulk moduli of boron nitride and boron carbonitride
(C0.33(BN)0.67) with good accuracy. By simulating several systems of
formula (C
x
(BN)1-x
) over a wide range of carbon contents
(x=0 to 1), we observed the same trends in the deviation from ideal mixing
as found experimentally. We attribute this deviation to the
relatively longer C-N bonds distributed randomly throughout the
intermediate C content systems.
Application of Infrared Attenuated Total Reflection Spectroscopy to In Situ Analysis of Atheromatous Plaques in Aorta
Authors: Atsushi Nakamura Atsushi Nakamura , Takehiro Koga Takehiro Koga , Makoto Fujimaki Makoto Fujimaki , Yoshimichi Ohki Yoshimichi Ohki , Takayuki Sota Takayuki Sota , Kristina Lipinska-Kalita Kristina Lipinska-Kalita , Tsuneyuki Nagae Tsuneyuki Nagae , Shin Ishimaru Shin Ishimaru , Katsuo Aizawa Katsuo Aizawa
Published: October 2002

Ex vivo infrared attenuated total reflection (ATR) spectroscopic studies have been carried out to observe the accumulation of cholesterol ester in atheromatous plaques. It has been found that ATR spectra can be successfully obtained from the intima side of aorta and give the same information as the transmission spectra. This means, the ATR spectra include information about the chemical composition of atheromatous plaques together with the degree of eventual lesions. We have demonstrated that ATR microspectroscopic measurements can give images of atheromatous plaques distribution and enable in situ observation of the relative amount of accumulated cholesterol ester. The results clearly indicate that the ATR spectroscopy enables spectroscopic diagnoses in vivo as well as in vitro.
Molecular-Beam Epitaxial Growth of Short-Period (001) Al/Ag/Cr Superlattices with Intermediary Ag Layers
Authors: Toshiki Kingetsu Toshiki Kingetsu , Yasuhiro Kamada Yasuhiro Kamada , Masahiko Yamamoto Masahiko Yamamoto
Published: October 2002

We studied the growth behavior and structures of molecular-beam-epitaxy-grown (001) Al/Ag/Cr superlattices, using reflection high-energy electron and X-ray diffraction analyses. (001) Al/Ag/Cr superlattices with a short period of about 1 nm were successfully grown on Cr buffer layers formed on MgO substrates. Epitaxial growth proceeds
with Al(001)[010]fcc ∥ Ag(001)[010]fcc ∥ Cr(001)[110]bcc. Al layers grow in the layer growth mode when one-monolayer Ag layers are formed on Cr underlayers, although Al deposited directly on Cr layers grows in the Stranski-Krastanov mode. Moreover, (001) growth of the Al/Ag/Cr superlattices is stable when the Cr layers are three monolayers in thickness, despite the fact that the growth of the (001) Al/Ag superlattices is rather unstable.
Loss Reduction of GeO2-Doped Silica Waveguide with High Refractive Index Difference by High-Temperature Annealing
Authors: Kashimura Seiichi , Takeuchi Manabu , Maru Koichi , Okano Hiroaki
Published: October 2002

The effect of a GeO2-doped core on high-temperature
annealing has been investigated to reduce the propagation loss of a
waveguide device with high refractive index difference (Δ). A
SiO2–GeO2 waveguide core was prepared on a fused silica
substrate by rf magnetron sputtering and reactive ion etching. With
increasing the annealing temperature, the roughness of the core
side-wall gradually disappears and the rectangular core gradually
becomes rounded. The effect of smoothing and rounding the cores was
a significant reduction of the scattering loss, and moreover, it
enabled the complete embedding of narrow gaps between cores in
cladding glass using conventional plasma chemical vapor
deposition. The propagation loss of the waveguide with a Δ of 1.5%
was 0.07 dB/cm at 1.55 µm wavelength, the effect of which was
demonstrated in the fabrication of an arrayed-waveguide grating
demultiplexer.
Electro-Optic Characteristic of Fringe-Field Switching Mode Depending on Rubbing Direction
Authors: Hong Seung Ho , Park In Cheol , Kim Hyang Yul , Lee Seung Hee
Published: October 2002

A recently developed new liquid crystal display, which operates
in the fringe-field switching mode, is known to exhibit high
transmittance as well as a wide viewing angle unlike the
conventional in-plane switching (IPS) mode display. The device shows
unique electro-optic behavior, nevertheless the liquid crystal
director rotates almost in-plane as in the IPS mode. We found that
light efficiency decreases as the rubbing angle with respect to the
horizontal component of the fringe field decreases for a liquid
crystal with positive dielectric anisotropy, whereas this is not
observed for a device driven by the in-plane field. In this paper,
the switching mechanism and voltage-dependent transmittance
characteristics with respect to rubbing directions have been
investigated.
ZnO Film Growth on (0112)LiTaO3 by Electron Cyclotron Resonance-Assisted Molecular Beam Epitaxy and Determination of Its Polarity
Authors: Kiyoshi Nakamura Kiyoshi Nakamura , Tatsuya Shoji Tatsuya Shoji , Hee-Bog Kang Hee-Bog Kang
Published: October 2002

Single-crystal ZnO films were grown on (0112)LiTaO3 substrates by electron cyclotron resonance-assisted molecular beam epitaxy (ECR-assisted MBE). The film orientation differed with the ratio of oxygen to zinc. Under oxygen-rich conditions, (1120)ZnO films with the c-axis parallel to the substrate surface were epitaxially grown. To identify the polarity of ZnO films with the c-axis parallel to the surface, a method using sideways chemical etching was proposed. The polarity of ZnO films was different when the films were grown on the + plane or the - plane of (0112)LiTaO3 substrates. The ZnO/LiTaO3 substrates offer a high electromechanical coupling factor of the shear horizontal-type leaky surface acoustic wave (SH-type leaky SAW) propagating along the X-axis due to an additional contribution of the piezoelectric shear effect of ZnO.
Observation of Transverse Dust Lattice Wave Excited by Unstable Vertical Oscillations of Dust Particles in an Ion Sheath with Low Gas Pressure
Authors: Misawa Tatsuya , Nunomura Shota , Ohno Noriyasu , Takamura Shuichi
Published: October 2002

A self-excited transverse wave propagating along a one-dimensional dust chain,
which is levitated around the plasma-sheath boundary, has been clearly observed in the
plasma with a low gas pressure using a high-speed intensified charge-coupled device
(ICCD) camera. The vertically polarized transverse wave was found to be excited due to
the positional dust instability. The frequency and wavelength obtained from the
experimental observations have been found to satisfy the dispersion relationship
theoretically predicted for the transverse dust lattice wave.
Fabrication of Nitrogen-Doped Diamond Field Emitter Utilizing Porous Silicon and Molding Technique
Authors: Takayuki Takida Takayuki Takida , Kouji Inoue Kouji Inoue , Sung-Gi Ri Sung-Gi Ri , Hideki Kimura Hideki Kimura , Hideo Kiyota Hideo Kiyota , Ichiro Saito Ichiro Saito , Tateki Kurosu Tateki Kurosu , Masamori Iida Masamori Iida
Published: October 2002

A nitrogen-doped columned-structure diamond field emitter (CSDFE) was fabricated by utilizing a molding technique on porous silicon (PS). The diamond film was deposited by the hot filament chemical vapor deposition method on a PS substrate after PS was seeded by diamond powder (less than 0.5 µm diameter) which acted as the nucleus. Electron emission and the stability of CSDFE were measured. It was found that at a lower electric field, that is, about 2.5 V/µm, the emission current of the CSDFE was higher than that prepared by an as-grown nitrogen-doped diamond field emitter. The emission current of the CSDFE was stable for a long operating time of over 8 h.
Improvement of Polysilicon Oxide Integrity Using NF3-Annealing
Authors: Yang Wen Luh , Shieh Ming Sun , Chen Yu Min , Chao Tien Sheng , Liu Don-Gey , Lei Tan Fu
Published: October 2002

We report a method to improve the polysilicon oxide integrity by using
NF3-annealing. Incorporating with stronger Si–N and Si–F bonds at the
polysilicon/ polyoxide interface, significant improvements are found in terms of
roughness, breakdown strength, charge-to-breakdown, and
stress-induced-leakage-current.
Vertical-Cavity Surface-Emitting Laser Array on GaAs(311)B Substrate Exhibiting Single-Transverse Mode and Stable-Polarization Operation
Authors: Arai Masakazu , Nishiyama Nobuhiko , Shinada Satoshi , Matsutani Akihiro , Koyama Fumio , Iga Kenichi
Published: October 2002

We have demonstrated a single-transverse-mode and stable-polarization GaInAs/GaAs vertical-cavity surface-emitting laser (VCSEL) array grown on a GaAs(311)B substrate. A fabricated 3×3 VCSEL array consists of devices with an oxide aperture of 3.4 µm×3.4 µm and exhibited single-transverse mode operation with an injection current up to three times the threshold. The Side-mode suppression ratio (SMSR) is larger than 30 dB. The array also exhibits stable-polarization operation with an orthogonal polarization suppression ratio (OPSR) of over 25 dB. The threshold current was 0.61±0.05 mA and the threshold voltage was 1.79±0.03 V. The obtained uniform single-mode array characteristics are due to the high uniformity and controllability of the improved oxidation process.
Coincidence of Density Jump and Plasma Emission Front Induced by Transversely Excited Atmospheric-Pressure CO2 Laser Bombardment at Low and High Pressures
Authors: Marpaung Mangasi , Pardede Marincan , Hedwig Rinda , Kurniawan Hendrik , Lie Tjung Jie , Kagawa Kiichiro
Published: October 2002

In order to confirm the validity of a model of laser-induced shock-wave plasma generation, the highly sensitive detection of density jump caused by a shock wave was carried out simultaneously with the emission of propelled atoms from a target. A special interferometer which utilized rainbow refractometry was devised. The laser light of a Transversely Excited Atmospheric-pressure (TEA) CO2 laser (600 mJ, 100 ns) was focused on non metal targets. The front of the propelled atoms and the front of the blast wave almost coincide and move together at the same speed during the initial stage of the plasma expansion. During the later stage, however, the front of the propelled atoms begins to fall behind.
Epitaxial Growth of 3C-SiC on Thin Silicon-on-Insulator Substrate by Chemical Vapor Deposition Using Alternating Gas Supply
Authors: Shimizu Toshiki , Ishikawa Yukari , Shibata Noriyoshi
Published: October 2002

Epitaxial 3C-SiC film has been grown on thin silicon-on-insulator (SOI) substrate by chemical vapor deposition (CVD) using an alternating supply of SiH2Cl2 and C2H2. The SiC surface deposited on SOI substrate is almost flat with few hillocks, and the full-width at half maximum (FWHM) of the X-ray diffraction (XRD) peak of the SiC(111) was 0.2°. Use of a thin SOI substrate is found to be essential to suppress the growth of voids that appear at the SiC/Si interface.
Electron Microscopic Study on the Initial Stages of (111)-Oriented Diamonds Grown on Pt Substrates
Authors: Jiang Nan , Kujime Susumu , Yamamoto Hirofumi , Inaoka Takeshi , Naoi Yoshiki , Shintani Yoshihiro , Makita Hiroshi , Hatta Akimitsu , Hiraki Akio
Published: October 2002

The initial stages of (111)-oriented diamonds grown on Pt substrates have been studied by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM images clearly reveal that scratching pretreatment strongly damages the surfaces of (111)-Pt substrates. After pretreatment, the column like polycrystalline damage layers are observed to form on the Pt surfaces for the first time, the average thickness of which is about 400 to 500 nm. During the subsequent deposition process, these surface damage layers gradually recrystallized into the single-crystalline state. The nucleation and initial growth of diamond particles are, in fact, accompanied by the Pt surface recrystallization process, and the formation of the (111)-oriented diamond grains is discussed in regard to the Pt surface recrystallization process.
Microscale Wear Properties of Ultrathin Diamond-Like Carbon Films
Authors: Shimura Ken-ichi , Baba Kazuhiro
Published: October 2002

Microscale wear properties of ultrathin diamond-like carbon (DLC) films grown by rf plasma-enhanced chemical vapor deposition were investigated using an atomic force microscope. It was revealed that a low wear-resistant layer, which contained a larger s
p
2 component, existed on the surface of the films. The thickness of the layer depended on the self-bias voltage during deposition. The intermixing of carbon and silicon atoms at the interface between the DLC and the substrate was found to affect the surface wear resistance of ultrathin DLC films.
Experimental Evidence for the Aggregation of the Near-IR Bands in BaFBr:Eu2+ Single Crystals
Authors: Toshio Kurobori Toshio Kurobori , Manabu Kawabe Manabu Kawabe , Min Liu Min Liu , Yukio Hirose Yukio Hirose
Published: October 2002

New experimental evidence for the aggregation of the near-IR
bands in BaFBr:Eu2+ crystals has been demonstrated
through a series of measurements on their emission in IR,
the nonrecombination process in additively colored crystals,
and the time-resolved absorption spectra. It was found that
the origin of the bands is attributed to a cluster of
F(Br-) centers.
Three-Dimensional Optical Recording on a Polyester Film Having Photochromic Thioindigo Moieties in the Main Chain
Authors: Fukaminato Tuyoshi , Kawai Tsuyoshi , Irie Masahiro
Published: October 2002

Three-dimensional optical recording with confocal microscopy was carried out. As the recording medium, a polyester film having fluorescent photochromic thioindigo moieties in the main chain was used. Upon irradiation with focused 568 nm light from an Ar–Kr laser, the fluorescent trans forms in the film were converted into non-fluorescent cis forms. The small recorded regions were detected as dark spots by using the same laser as the reading light source. The size of the dark spots was approximately 300 nm in width and 1.5 µm in depth, which corresponds to a recording density of more than 5 Gbit/mm3.