bluuebunny/crossref_metadata_2025 huggingface dataset:
Design Considerations for Silicon Circular Diaphragm Pressure Sensors
Authors: Yasukawa Akio , Shimada Satoshi , Matsuoka Yoshitaka , Kanda Yozo
Published: November 2005

The design of silicon circular-diaphragm pressure sensors was considered in order to develop highly-accurate pressure sensors. A relatively simple method of stress analysis was proposed. The anisotropy of the elastic properties of silicon, the large deflections of the plates, and elastic deformations of the support structures were taken into account in the stress analysis by the plate theory and the finite element method. Output voltages and their nonlinearities were calculated by applying stress analysis and piezoresistive sensor theories. The calculated results are in close agreement with the experimental results.
Electrical and Photoelectrical Characterization of n·GaxAl1-xSb–p·GaSb Heterojunction
Authors: Shen Jingxiang , Kitamura Noboru , Kakehi Masahiro , Wada Takao
Published: November 2005

A heterojunction of n·Ga
x
Al1-x
Sb–p·GaSb was prepared by vapor-phase deposition in a conventional closed-tube system with iodine as a transport agent. Electrical and photoelectrical characterization was carried out on the heterojunction diodes. The I-V characteristics showed that η in the forward current varied between 1 and 2 in the experimental range 206–300 K. The C-V measurements indicated that the heterojunction was an abrupt one with a diffusion potential of 0.65 V. The spectral photovoltaic response gave a broad peak between 1.35 and 1.55 µm.
Monte Carlo Calculation on Neutral Gas Transport and Impurity Production in a Toroidal Plasma
Authors: Murase Kenya
Published: November 2005

The spatial distribution of the neutral gas and the energy distribution of escaped neutral particles in a toroidal plasma are investigated using the Monte Carlo technique. These measurements are important in estimating the charge exchange loss of the fast ions produced in neutral beam injection heating, for data analysis in neutral particle detection, etc. Taking a fairly large value for the major radius of the torus, a comparison with other calculations in an infinite cylinder is carried out and satisfactory agreement is obtained within the range of statistical error. A method is also presented, for estimating the influx of impurities due to sputtering from the wall surface by escaped neutral atoms.
Kinetic Model for Self-Sustained Discharge XeCl Lasers
Authors: Maeda Mitsuo , Takahashi Akihiko , Mizunami Toru , Miyazoe Yasushi
Published: November 2005

A simulation code including the Boltzmann equation which describes the kinetics of the self-sustained discharge XeCl laser is developed. The performances of four different gas mixtures, HCl/Xe/Ne, HCl/Xe/He, F2/Kr/Ne and F2/Kr/He are compared under the same conditions, and the buffer gas effect is discussed in detail. The HCl/Xe/Ne system shows the best performance. With the Ne buffer gas, the elastic collision loss is remarkably small, whereas the electric circuit loss is large owing to the low discharge resistance. The results on the variation of the input energy and total pressure are qualitatively consistent with the experimental results. Useful knowledge on the design of efficient XeCl lasers is obtained.
Energy Loss of High-Density Hot Carriers in Polar Semiconductors
Authors: Sato Hisanao
Published: November 2005

The rate of energy loss of hot carriers is calculated as a function of the carrier density by assuming that the energy loss is due to interactions with longitudinal optical phonons. It is found that for low effective mass carriers, both the screening and the Fermi degeneracy greatly reduce the energy loss even at room temperature.
Plasma Focus Breeder
Authors: Ikuta Kazunari
Published: November 2005

It is possible to breed fissile fuels with the help of a high current plasma focus device instead of using linear accelerators. A mechanism for accelerating a proton beam in a plasma focus device to a high energy would be the change of inductance in the plasma column caused by a rapid growth of plasma instability. A possible scheme for a plasma focus breeder is proposed.
Alignmental Deterioration of Homeotropically Aligned Liquid Crystal Cells under DC Electric Field. II. Relationship of Deterioration to Surface Property Change
Authors: Nakano Fumio , Satoh Mikio
Published: November 2005

Changes in the surface properties of Indiumoxide electrodes in liquid crystal cells with homeotropically aligned doped nematics were investigated when a dc voltage was applied to clarify the relationships between those changes and alignmental deterioration. Contact angle measurements showed that only the energy of the cathode surface increased. Auger spectra suggest that the changes in surface energy are caused by a reduction of In2O3. The changes apparently cause the film on the surface of the electrode to break away from the surface. The deterioration process apparently occurred as follows. First, the reduction of In2O3 occurred on the cathode and the surface film broke away. This caused the surface energy to increase and that initiated alignmental deterioration.
Aluminum Reactive Ion Etching Employing CCl4+Cl2 Mixture
Authors: Horiike Yasuhiro , Yamazaki Takashi , Shibagaki Masahiro , Kurisaki Tetsuo
Published: November 2005

Alumintun reactive ion etching has been investigated employing a CCl4+Cl2 mixture. Anisotropic etching was achieved at a self-bias voltage of –150V, a flowrate concentration of 50% Cl2 in CCl4 and 13.56 MHz rf power at 200 W. The photo-resist swelling, which is closely related to undercutting of the isotropic etching condition is attributed to the heat of reaction between neutral reactive species and Al. A mass analysis makes it clear that a CCl4+Cl2 plasma generates more CCl+
3 species while suppressing unsaturated monomers, and also reduces the water vapor. Decreasing the final pressure in the reactor shortens the initiation period, then it disappears for the anisotropic etching condition with CCl4+Cl2. A “load-lock” type reactor is confirmed to offer reproducible Al etching. Blowing hot air (\doteqdot200°C) over the wafers after etching was found to be an effective measure against rapid Al corrosion.
Solute Redistribution in Laser Crystallization in Concentrated InAs–GaAs Alloy
Authors: Matsuura Makoto , Nishinaga Tatau , Suzuki Akira , Yuitoh Mitsuhiro , Yasuda Yukio , Nakamura Tetsuro
Published: November 2005

Solute redistribution in an ultra-high-speed recrystallization induced by pulsed laser was investigated in concentrated In
x
Ga1-x
As alloys (x=0.12 and 0.13) and in GaAs by Auger analysis. Because oxygen in the air is likely to affect the depth profiles in a surface region irradiated by laser light, we observed the solute distribution in the initial transient region as well as in the final transient one. From the depth profile up to 2.5 µm, we have concluded that the effective distribution coefficient of In in In
x
Ga1-x
As is nearly unity at a high growth velocity such as that occurring in laser crystallization.
Speed Distribution of Monatomic, Diatomic and Polyatomic Molecular Beams Scattered by the (111) Plane of Silver
Authors: Asada Hiromu , Matsui Toshiji
Published: November 2005

The speed distribution of Ne, Ar, N2, O2, NO, CO, CO2, and CH4 molecular beams scattered by Ag (111) surfaces was observed for an incident energy of 78–88 meV, an incident angle of 50°, and a surface temperature of 500 K. The sensitivity of the mean speed and mean energy to the scattering direction is found to be correlated with the symmetry of the scattered molecules, i.e., monatomic\gtrapproxlinear symmetric>linear asymmetric≈CH4, while the behavior of the standard deviation of the speed distribution parallels that of the width of the spatial distribution of the scattered flux when the different gases are compared.
Crystallographic Character of ZnO Thin Film Formed at Low Sputtering Gas Pressure
Authors: Miura Michiyori
Published: November 2005

The crystallographic character of ZnO thin films formed by the rf sputtering technique were investigated using X-ray diffraction and RHEED.
When the sputtering gas pressure is 5×10-3 Torr, there is no preferred orientation of the crystal axis near the surface of ZnO thin film, but below its surface, the c-axis is oriented normal to the substrate within a certain distribution angle. The crystallites reorient so that the c-axes are normal to the substrate as new surface layers are formed.
Abnormal Transverse-Field Effects in Nonideal Type II Superconductors I. A Linear Array of Monofilamentary Wires
Authors: Funaki Kazuo , Yamafuji Kaoru
Published: November 2005

When an AC magnetic field was applied in the axial direction to a linear array of superconducting monofilamentary wires in the presence of a DC magnetic field perpendicular to the axes of the wires, it was found that the component of flux along the DC field changed its semi-quasistatic distribution in each cycle of the AC field and finally reached a uniform distribution after several tens of cycles. In the steady state, the AC component of flux showed a distribution of the Bean-London type with a reduced pinning force. For a small amplitude of AC field, the observed hysteresis loss increased with increase in the DC field. All of these characteristics exhibit a striking contrast to those of the so-called longitudinal-field effects, and may be called abnormal transverse-field effects; they have not been observed until now.
Density Matched Coating for Laser Fusion Targets
Authors: Tsujimoto Akira , Norimatsu Takayoshi , Izawa Yasukazu , Yamanaka Chiyoe
Published: November 2005

A new technique for the graded density coating on a glass-microballoon has been developed using the copolymerization by means of plasma polymerization. A coating layer linearly varied in density from 1.82 gcm-3 to 0.8 gcm-3 was obtained.
Dry Cleaning of Si Surface Contamination by Reactive Sputter Etching
Authors: Kuwano Hiroki , Miyake Shojiro , Kasai Toshio
Published: November 2005

A dry cleaning method is needed at present in Si wafer processing. We investigated the removal of Na contamination from an Si surface by a reactive sputter etching method. The surface contamination was analyzed by SIMS, AES and ESCA, and the results showed that this dry cleaning technique can decrease Na contamination under low gas pressure and high RF power if a CF4+O2 gas mixture is used. However, a saturated Na contamination value exists because of reattachment of Na atoms sputtered from the surface of the sample, the cathode and the chamber walls. Fluorine plays an important role in removing the Na. Na atoms combine with F atoms, and are then sputtered from the surface in this cleaning method. F and C atoms are removed from the surface as CO
x
and COF
x
as the relative flow rate (O2/CF4) increases.
Fabrication of Submicron Pattern with an EB Lithographic System Using a Field Emission (FE) Electron Gun
Authors: Hosaka Sumio , Ichihashi Mikio , Hayakawa Hajime , Nishi Sadaaki , Migitaka Masatoshi
Published: November 2005

This paper describes the advantages of an EB Lithographic system using an FE electron gun and steered-beam vector scan to fabricate submicron patterns. Application of this system to submicron pattern writing is studied through exposure intensity distribution (EID) and exposure dosage for submicron patterns. The system can carry out submicron pattern writing with high resolution and small proximity effect. For example, the system provides submicron resist patters with line width larger than 0.5 µm and gap spacing 1.0 µm without proximity effect correction. The application of this system to VLSI submicron pattern writing is also demonstrated.
Correlation between Types of Junction and Submillimeter-Wave Responses in Point-Contact Josephson Junctions
Authors: Morita Seizo , Noguchi Takashi , Takaki Satoru , Horii Shinichi , Imai Syozo , Takeuti Yosihisa , Mikoshiba Nobuo
Published: November 2005

It has been found that point-contact Josephson junctions can be clearly classified into bridge-type and tunnel-type by introducing new parameters characterizing their I-V curves. Nearly-ideal tunnel-type junctions with Nb–SuO
x
–Sn (Film) point-contacts were obtained. Tunnel-type junctions showed larger gap energies than bridge-type junctions in Nb–SnO
x
–Sn and Nb–NbO
x
–NbN point-contacts. The submillimeter-wave responses were measured in Nb–Nb point-contacts, and it was found that the contacts with the best performance were bridge-type junctions with a sharp gap structure; tunnel-type junctions showed rather bad performance. On irradiation with laser light, the center of the Shapiro step moved to the lower-current side in bridge-type junctions but to the higher-current side in tunnel-type junctions. These differences can be explained by differences in the heating effects between bridge-type and tunnel-type junctions.
Characterization of Thermally-Induced Defects in CZ–Si by Room-Temperature Photoluminescence
Authors: Katsura Johji , Nakayama Hiroshi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

Microdefects in CZ–Si wafers induced by heat treatment in the 400–900°C temperature range have been investigated by photoluminescence (PL) measurements at room temperature. It has been found that thermally-induced defects act as nonradiative recombination centers and are very sensitive to the room-temperature PL intensity. The etch-pit density corresponding to these defects shows a strong correlation to the PL intensity. As a result, this room-temperature PL method seems to be very useful for the characterization of LSI-grade Si wafers annealed by various thermal processes.
Electronic Conduction in Epitaxial Aluminum Nitride Films on Silicon
Authors: Morita Mizuho , Tsubouchi Kazuo , Mikoshiba Nobuo
Published: November 2005

Measurements of current-voltage and current-temperature characteristics have been performed on metal-aluminum nitride (AlN)-silicon (n+–Si) substrate structures with Au and Al as metal electrodes. Single-crystal AlN films were epitaxially grown on (111)-oriented Si substrates by metalorganic chemical vapor deposition (MO–CVD). At room temperature it was found that the current-voltage characteristics show Ohmic behavior at low fields and the resistivity is of the order of 1016 \varOmegacm. On the other hand, it was found at high fields that the current is controlled by the Poole-Frenkel conduction of holes or electrons. Values of the hole trap energy depth from valence band edge and the electron trap energy depth from conduction band edge were found to be about 0.5 and 0.9 eV, respectively.
Film Thickness Allowance and Waveguide Length in 3-Layer Unidirectional Magneto-Optical TE-TM Mode Converter
Authors: Abe Masanori , Nakagawa Hidenobu , Gomi Manabu , Nomura Shoichiro
Published: November 2005

The film thickness allowance and the waveguide length in a 3-layer (substrate/film/air) magneto-optical unidirectional TE-TM mode converter which utilizes the intrinsic birefringence in an anisotropic material are calculated at λ0=1.55 µm. The film material should be gyrotropic in order to make the waveguide length short, and the film thickness allowance is relaxed by reducing the ratio of the dielectric constant of the film to that of the substrate. When the waveguide is made of an isotropic gyrotropic film of YIG deposited on an anisotropic substrate (which may be gyrotropic or not), the restriction on the film thickness can in practice be removed, but this requires precise control of the dielectric constant of the film and the substrate instead.
An Investigation of the Properties of an Epitaxial Si Layer on a Substrate with a Buried SiO2 Layer Formed by Oxygen-Ion Implantation
Authors: Homma Yoshikazu , Oshima Masaharu , Hayashi Takayoshi
Published: November 2005

We have investigated the crystallographic properties of a silicon substrate with a buried SiO2 layer formed by oxygen-ion implantation (16O+ dose: 1.2 to 2.4×1018/cm2) and an epitaxial silicon layer on the substrate using the step-by-step sample thinning technique. The surface silicon layer on the buried SiO2 layer was found to have a dislocation-free single-crystalline silicon region, but with small precipitates of oxide. The epitaxial silicon layer grown on the surface silicon layer was found to have a high density of dislocations. The dislocation density was 2×109/cm2 and was almost constant for a substrate oxygen dose above 0.6×1018/cm2. The dislocations are considered to be caused by precipitates in the surface silicon layer. However, the epitaxial layer had fairly high mobility and no stacking faults.
Normal-Super Transformation of Liquids: The Minimum Drop Studied by SEM
Authors: Takahashi Ryoji
Published: November 2005

A microdrop was created by stopping an electron probe on the surface of hydrated metaphosphoric acid. It was photographed for various sizes of specimen, accelerating voltage of the probe and irradiation time. The mechanism of microdrop creation was explained by Laplace's equation, p-p'=2γ/R, where p and p' show the vapor pressure of water in the specimen and in the instrument, γ and R show the surface tension and the radius of the specimen. p is increased locally by the irradiation, and a new droplet with small R is created. The microdrop was found not to be decreased under a limited diameter D
min, 1.1 µm for this specimen. A liquid smaller than the minimum drop is free from surface energy and behaves as a super (lubricant) liquid by a change in structure. The normal-super transformation of liquids explains many problems lying in micron region.
Characteristics of Pulsed Molecular Beams from an Electromagnetic Valve
Authors: Teshima Koji , Yasunaga Yoshifumi
Published: November 2005

Pulsed molecular beams of about 5 msec duration of room temperature argon from an electromagnetic valve are examined, and their intensities, conditions for the optimum nozzle-skimmer distances and source pressures, with a flat beam intensity, and their speed ratios were measured. The optimum conditions were obtained for the Knudsen number based on the skimmer orifice K
n
s=2–6. The dependence of the beam intensity for the optimum conditions on the source pressure agrees very well with a modified expression given here based on the sudden freezing model. The attainable speed ratios agree with the semi-empirical relation of Anderson and Fenn.
Crystal Structure and Morphology of Fine Particles of Vanadium Silicides
Authors: Ishimasa Tsutomu , Fukano Yasushige
Published: November 2005

In this experiment, fine particles of various vanadium silicides were made by the gas-evaporation technique. The structure and morphology of the particles were observed by electron microscope. The A15 structure was found to appear at 20.0 and 25.0 at.%Si, while the D88 and D8
m
structures appeared at 35.2 and 37.5 at.%Si. The particles were surrounded by crystallographic planes with low Miller's indices characteristic of each structure. At 30.0 and 32.7 at.%Si, two types of particle were observed; one containing the A15 and D8
m
structures and the other the A15 and D88 structures. In the respective particles, the lattice relationships (001)A15//(001)D8
m

and [100]A15//[100]D8
m

, and (001)A15//(001)D88
and [110]A15//[120]D88
, were found. These can be ascribed to the resemblance between the structures.
Photoluminescence in Amorphous C: H Films Prepared by Glow Discharge Decomposition of CH4 or C2H6
Authors: Watanabe Ichiro , Inoue Makoto
Published: November 2005

Hydrogenated amorphous carbon films have been prepared by glow discharge decomposition of CH4 or C2H6 gas. The films exhibit white photoluminescence with high efficiency and weak temperature dependence which can be observed even at room temperature. The peak energy and intensity of the emission band vary depending on gas temperature during glow discharge. The high efficiency and weak temperature dependence are suggested to result from a strong Coulomb interaction in photoexcited electron-hole pairs.
Light-Induced Degradation of Semiconductor Surfaces as Studied by Photoacoustic Spectroscopy: Photodarkening Process of ZnxCd1-xS: Ag, Al Phosphors
Authors: Ohba Yasuo , Mizuta Masashi , Kukimoto Hiroshi
Published: November 2005

A photoacoustic technique has been applied for studying light-induced darkening of Zn
x
Cd1-x
S: Ag, Al phosphors in various gas ambients. The threshold energy and the rate for the light-induced darkening depend on the bandgap energy of the materials. The darkening process occurs effectively in the mixed ambient gases of N2, CO2 and H2O which are the components of air. A bleaching process has also been observed in a mixture of O2 and H2O.
Frequency Stabilization of AlGaAs Semiconductor Lasers with External Grating Feedback
Authors: Sampei Seiichi , Tsuchida Hidemi , Ohtsu Motoichi , Tako Toshiharu
Published: November 2005

The frequency of AlGaAs semiconductor lasers with external grating feedback has been locked to a Fabry-Perot interferometer by controlling the external cavity length with a PZT. The lasers were tunable over a wavelength range of 3.0∼4.5 nm. The frequency stability of 8.0×10-10≧σy≧3.2×10-12 was obtained for 1 ms≦τ≦100 s.
Impact Radiative Fusion Concept
Authors: Yabe Takashi , Mochizuki Takayasu
Published: November 2005

This letter proposes a new, fascinating ICF scheme. The scheme employs the soft x-ray production by hypervelocity projectiles. The soft x-ray of 1013 W/cm2 and 10 nsec duration, which is focusable onto a small sized pellet, can be efficiently produced.
Effect of Double Doping on Electrical Conductivity of Poly-p-Phenylenesulfide
Authors: Yoshino Katsumi , Kyokane Jun , Ozaki Masanori , Yun Mun Soo , Inuishi Yoshio
Published: November 2005

The electrical conductivity of PPS doped with TCNQ is of the order of 10-8 S/cm and higher than that of non-doped PPS by more than ten orders of magnitude. By the exposure of this TCNQ doped PPS to I2 vapor, the conductivity increases an additional four orders of magnitude. For the single doping of TCNQ, the maximum conductivity is obtained at about 10% (weight%) of TCNQ. But in the case of double doping, a maximum conductivity as high as 10-3 S/cm is obtained for the PPS containing 3% of TCNQ, which is also much higher than the conductivity obtained by single doping of I2 (10-8 S/cm).
Prevention of Surface Corrugation Thermal Deformation for InGaAsP/InP DFB Lasers
Authors: Nagai Haruo , Noguchi Yoshio , Matsuoka Takashi , Suzuki Yoshio
Published: November 2005

Thermal deformation mechanism for surface corrugations fabricated on InP and InGaAsP crystal surfaces has been analyzed, and threshold value existence for PH3 partial pressure in H2 ambient to prevent the deformation is shown. It has been verified that as-fabricated corrugation height can be conserved even after the LPE process by preventing thermal deformation before growth and by retaining an adequate supersaturation for the growth melt. Applying the results of these studies, heterostructures for 1.3∼1.5 µm region DFB lasers with first order grating of near 1000 Å corrugation height have been fabricated.
Plasma-Enhanced Deposition of Silicon Nitride from SiH4–N2 Mixture
Authors: Katoh Kazuhisa , Yasui Masaru , Watanabe Hideo
Published: November 2005

Excellent silicon nitride films which can be used as the gate insulator of an a-Si FET are fabricated by RF glow-discharge of SiH4–N2–H2 gas mixtures. Resistivity of larger than 1×1016 Ω·cm and breakdown strength of 6×106 V/cm are realized. The optimum deposition conditions are evaluated and briefly discussed in connection with mechanisms of the plasma-enhanced deposition.
A 1.59 µm Wavelength GaInAsP/InP Distributed Feedback Laser with First-Order Grating on Anti-Meltback Layer
Authors: Uchiyama Seiji , Iga Kenichi
Published: November 2005

A 1.59 µm wavelength GaInAsP/InP distributed feedback laser with first-order grating has been fabricated by a two-step liquid phase epitaxial (LPE) growth. The first-order grating was formed on the anti-meltback layer grown on the active layer. The threshold current was 680 mA for 18 µm stripe width and 510 µm cavity length and single-longitudinal-mode operation was obtained from –50 to 0°C.
Degradation-Free P-CVD SiN Deposition on GaAs FETs
Authors: Yamane Yasuro , Ishii Yasunobu , Mizutani Takashi
Published: November 2005

The plasma enhanced chemical vapour deposition (P-CVD) silicon nitride (SiN) effect on normally-off GaAs FETs was examined. It was verified that positive ion bombardment effect brings about GaAs FET degradation.
A simple, improved method of successfully achieving damage free SiN deposition on GaAs FETs is proposed.
Al-coated variable thickness Pb microbridge.
Authors: Kobayashi Masanori , Musha Toshimitsu
Published: November 2005

To make a thin-film Pb microbridge durable against heat cycles, we coated thin Al film over a variable thickness Pb microbridge. It showed no detectable change in its electrical properties, critical current or normal resistance after 20 heat cycles and preseration for 250 hours in a humid environment.
Application of Amorphous-Silicon Field-Effect Transistors in Three-Dimensional Integrated Circuits
Authors: Nara Yasuo , Kudou Yoshimitsu , Matsumura Masakiyo
Published: November 2005

Amorphous-silicon field-effect transistors have been integrated into three-dimensional form for the first time, and the static as well as dynamic characteristics were evaluated. Inverters and nine-stage ring-oscillators fabricated on a fused silica substrate have two layers of FETs isolated by CVD SiO2. The inverters had step-like transfer characteristics and a small-signal gain of about 10 was obtained. The ring-oscillator experiment showed that the minimum proparation delay time per gate was about 60 µsec.
XPS Studies on Thermal Switching in Thick Film Al-VP Glass-Al Structure
Authors: Setty M. S. , Sainkar S. R. , Sinha A. P. B.
Published: November 2005

Thick film sandwich structures of Me-VP glass-Me (Me=Au, Al) have been prepared. The I-V characteristics are nonlinear in all cases but thermal switching has been observed only in Al-VP glass-Al structure. Presence of VO2 was identified from XPS studies in the vanadium phosphate glass in the post breakdown state.
Elect-Equimultiple Imaging with Stacked Distributed-Index Planar Microlenses
Authors: Oikawa Masahiro , Iga Kenichi , Morinaga Motoyasu
Published: November 2005

Four pieces of 2-D arrays of distributed-index planar microlenses (0.8 mmφ and f=2 mm) have been stacked to construct an imaging component. Its working distance was 20 mm and clear images with resolution of more than 20 line pairs/mm have been obtained.
ECR-Discharge Cleaning for Liner-Containing Tokamaks
Authors: Ishii Shigeyuki , Okazaki Kiyohiko , Sakamoto Yuichi , Yano Katsuki
Published: November 2005

An experiment on electron-cyclotron-resonance (ECR) discharge cleaning was conducted in the TEXTOR device. A clean-up time for the liner was determined by estimating a total atomic flux integrated over spatial distributions of the ECR plasmas. It was proved that the vacuum components between the liner and vacuum vessel of tokamaks can be cleaned by this method.
High Resolution Electron Microscopic Study of Oxide Particles Produced by the Coalescence of Smoke Particles of Iron and Iron Oxide
Authors: Kaito Chihiro
Published: November 2005

The structure of particles in a mixture of Fe smoke and γ-Fe2O3 smoke prepared by gas evaporation were investigated by crystal lattice imaging in high-resolution electron microscopy. Fe3O4, Fe3O4+Fe and Fe3O4+α-Fe2O3 particles are formed by the coalescence of Fe and γ-Fe2O3 particles above 350°C.
An Aluminum Liquid Metal Ion Source with Prolonged Lifetime Using a Sintered Boride Emitter
Authors: Torii Yasuhiro , Yamada Hiroshi
Published: November 2005

A field-emission liquid Al ion source with a sintered boride emitter, such as TiB2, BN-TiB2 composite, has been built to prolong the utilization term of an aluminum ion beam emission. In this approach, a stable Al ion beam emission was successfully obtained for more than 100 hours without any recognizable degradation. Emission current fluctuation was less than ±1% over 1 hour for 10 µA source ion current without any feedback stabilization. Moreover, 20–30 µA/sr angular intensity at 5–10 µA source ion current, 17° emission half-angle at 10 µA source current, and a large source ion current of more than 1.5 mA were also observed.
Crystallographic Structures and Perpendicular Magnetization of GdFe Films Sputtered with Substrate Bias Voltage
Authors: Nawate Masahiko , Ohkoshi Masatoshi , Honda Shigeo , Kusuda Tetsuzo
Published: November 2005

Crystallographic structures of sputtered Fe and GdFe films both with and without substrate bias voltage were investigated using an X-ray diffractometer. Films sputtered from lower Gd composition target show the crystalline phase. It was found that (110) orientation of bcc Fe in the films was improved by the small amount of incorporated Gd atoms with the existence of substrate bias voltage. Films possessing magnetization aligned perpendicular to the film plane were obtained with the application of -200 V and -300 V bias voltage to the substrate.
Life Test of 30 mW GaAlAs TAL Laser Grown by OMVPE
Authors: Vilms J. , Engelmann R. W. H.
Published: November 2005

Operating life data taken at 70 and 80°C at an output power level of 30 mW cw from one facet are presented for a protonisolated stripe, (Ga, Al)As Thin Active Layer DH laser grown by Organo-Metallic Vapor Phase Exitaxy, and mounted epi-side up on a Si submount with Sn solder. Median life of 450 h at 80°C ambient and 2500 h at 70°C ambient was observed. The failure mode is gradual increase of threshold current combined with decrease of the kink power level below the operating point.
Radiation Damage in Epitaxial CaF2 Films on Si Substrates by Ar+ Ion Implantation
Authors: Ishiwara Hiroshi , Orihara Kouzo , Asano Tanemasa
Published: November 2005

Radiation damage in epitaxial CaF2 films on Si substrates produced by 150 keV Ar+ ion implantation has been investigated using Rutherford backscattering and channeling techniques. It has been found that CaF2 films are more stable than Si crystals for ion bombardment and are not amorphized at such a high dose as 6×1016 cm-2. Recovery of the damage by subsequent thermal annealing has also been investigated.
GaAs P-Layer Formation by Be Ion Implantation
Authors: Sugata Sumio , Tsukada Noriaki , Nakajima Masato , Kuramoto Kazuo , Mita Yoh
Published: November 2005

A novel, nearly hazardless Be ion implantation technique has been realized by adopting BeO ceramic material as an ion source. This method made possible a continuous Be ion current of several tens of µA without noticeable contamination. High dose Be ion implantation experiments were carried out using this technique and it has been found that Be atom activation can be improved by hot implantation and subsequent lower temperature annealing.
Fluxon Observation Using a Josephson Sampler
Authors: Sakai Shigeki , Akoh Hiroshi , Hayakawa Hisao
Published: November 2005

A single fluxon and a bundle of fluxons propagating on a Josephson transmission line are observed by means of the direct coupled Josephson sampler. The half width of the observed pulse is less than 10 ps, and is 6.0 ps under an optimum condition. It is found that the number of fluxons can be controlled by a dc bias current biased at the edge of the transmission line.
A Circuit for a Well-Controlled Sliding Spark
Authors: Kawata Shintaro , Aoki Sadao , Sakayanagi Yoshimi
Published: November 2005

The use of a new circuit for a sliding spark is described which has an electron beam controlled discharge without misfires and unwanted flashovers in its operation. Due to the well-controlled discharges by the circuit, about one thousand shots, which is several times more than the usual circuit, are possible with one capillary.
Distribution of the Main Electron Trap EL2 in Undoped LEC GaAs
Authors: Hasegawa Fumio , Iwata Naotaka , Yamamoto Norio , Nannichi Yasuo
Published: November 2005

The main electron trap EL2 is thought to be responsible for the semi-insulating nature of an undoped LEC GaAs for IC's. Distribution of this electron trap has been measured in this study by a normal DLTS method. It was found that the trap density of EL2 was as high as 3–5 ×1016 cm-3 taking into account the non-ionized front region of the depletion layer. Concentration of EL2 sometimes fluctuates by a factor of 2–3 within a wafer as well as from wafer to wafer. There was no dependence of EL2 density on etch pit density (EPD), however, when EPD was less than 2×105 cm-2. For samples with EPD above 2×105 cm-2, EL2 density increased slowly with an increase of EPD.
Kinetics of Plasma Deposition of a-Si:H Films
Authors: Hotta Sadayoshi , Okamoto Hiroaki , Hamakawa Yoshihiro
Published: November 2005

A series of systematic investigations have been made on the correlation between plasma deposition parameters and film properties. Glow discharge optical emission spectroscopy and their spatial distribution have been measured in a constant rf power as a function of the substrate-positive column distance. It has been clarified from the analysis of the depositionrate profiles that the transport of decomposed species compiled into the amorphous network is limited by the diffusion of the decomposed species superimposed by gas drift.
Effects of Sputter Etching on Aluminum-Silicon Schottky Barrier Diode Characteristics
Authors: Kikuchi Akira , Iwata Seiichi
Published: November 2005

Schottky barrier diodes are fabricated on silicon surfaces whose impurity concentration is controlled by ion implantation techniques. The barriers are produced by Al–Si film sputtering. The forward characteristics of the sputter etched Schottky barrier diode show a forward current higher than the predicted value for low voltages and a lower value at high voltages. Electron spectroscopy for chemical analysis reveals that the silicon surface is contaminated with oxidized aluminum and molybdenum and with entrapped argon atoms during the sputter etching process.
Fabrication of Si:H Alloy with Plenty of –SiH3 by Reactive Sputtering onto Low Temperature Substrate
Authors: Miyasato Tatsuro , Abe Yuji , Tokumura Masao , Imura Takeshi , Hiraki Akio
Published: November 2005

Si:H alloy with strong infrared absorption bands due to the –SiH3 group was fabricated by means of a planar magnetron r.f. sputtering technique in hydrogen gas onto a low temperature substrate. The content of the –SiH3 group increases greatly by cooling down the single crystal silicon wafer substrate to about -60°C. The deposition rate was 1200 Å/min. The deposit Si:H alloy is composed of microcrystalline grains with a uniform polyhedron or spherical shape and a uniform diameter of 100 Å.
Growth of ZnS by Metalorganic Chemical Vapor Deposition
Authors: Fujita Shigeo , Tomomura Yoshitaka , Sasaki Akio
Published: November 2005

ZnS epilayers are grown on GaP and GaAs substrates by a low pressure metalorganic chemical vapor deposition technique using dietylzinc (DEZ) or dimethylzinc (DMZ) and H2S as source materials. Good epitaxial layers of ZnS are grown at a substrate temperature T
G of 370 to 400°C at a flow rate ratio, [H2S]/[DEZ] or [DMZ]≃3.0. A typical growth rate of ZnS layers at T

G
=375°C is ∼4 µm/hr for the DEZ/H2S system and ∼3 µm/hr for the DMZ/H2S system.
Dry Liftoff Method by Sublimation of Molybdenum Oxide
Authors: Yamauchi Noriyoshi , Yachi Toshiaki , Wada Tsutomu
Published: November 2005

A new liftoff method is proposed in which the film to be lifted-off is deposited on a molybdenum pattern. After the deposition, liftoff is done by thermally oxidizing the molybdenum and sublimating the molybdenum oxide. One micro meter thick sputter-deposited silicon dioxide was successfully delineated by this dry liftoff method. Dry liftoff is possible in an oxigen ambient at a temperature of 700°C or higher. The rate at which the molybdenum underneath the silicon dioxide is removed increases with the oxidation temperature and is typically 30 µm/min at 900°C.
Sm–Co Amorphous Film with Perpendicular Anisotropy
Authors: Lee Zo-Yi , Numata Takuhisa , Sakurai Yoshifumi
Published: November 2005

It is very difficult to prepare Sm–Co ferromagnetic film with perpendicular anisotropy, though RE–TM ferrimagnetic films with perpendicular anisotropy are well prepared (RE: rare earth, TM: transition metal). Because of the exceptional magnetic properties of Sm–Co magnetic film as magnetic recording media, we studied to prepare Sm–Co magnetic film with perpendicular magnetization. Films were deposited by a magnetron RF sputtering onto glass substrates (T
sub=80∼-100°C) and with a bias voltage (V
b=-60∼-80 V). The magnetic hysteresis loops, polar Kerr hysteresis loops and torque curves of this film are characterized by a uniaxial perpendicular anisotropy.
Improved Electron Mobility Higher than 106 cm2/Vs in Selectively Doped GaAs/N-AlGaAs Heterostructures Grown by MBE
Authors: Hiyamizu Satoshi , Saito Junji , Nanbu Kazuo , Ishikawa Tomonori
Published: November 2005

Electron mobility of quasi-two dimensional electron gas (2DEG) in selectively doped GaAs/N-Al
x
Ga1-x
As (x=0.3) heterostructures grown by MBE was investigated as a function of thickness of an undoped Al
x
Ga1-x
As spacer-layer (0–200 Å) introduced between a Si-doped AlGaAs layer and an undoped GaAs layer, at 77 K and 5 K. Mobility of 2DEG as high as 2,120,000 cm2/Vs at 5 K was achieved with a spacer-layer thickness of 200 Å. This electron mobility is higher than any observed so far in semiconductor materials.
Photoluminescence Investigation of Donor-Level Deepening in GaAs under Hydrostatic Pressure
Authors: Kobayashi Michihiro , Yokoyama Teruo , Narita Shin-ichiro
Published: November 2005

Hydrostatic pressure dependence of photoluminescence spectra in Se-doped GaAs has been measured at 1.5 K by using a diamond anvil cell up to 48 kbar. Two emission peaks due to bound-exciton annihilation and donor-acceptor recombination are observed under pressure. With increasing pressure the donor binding energy is found to become as deep as approximately 115 meV at 41 kbar where the crossover of the Γ1–X1 conduction band edges occurs.
Growth-Induced Optical Birefringence in LPE-Grown Bi-Based Iron Garnet Films
Authors: Ando Koji , Koshizuka Naoki , Okuda Takashi , Yokoyama Yuko
Published: November 2005

A growth-induced optical birefringence has been observed in Bi-based iron garnet films grown by LPE method. The lattice misfit dependence of the birefringence, which is estimated from the phase mismatch between TE and TM modes in the garnet thin film waveguide, shows the existence of optical anisotropy that can not be attributed to the stress in the film. This birefringence is ascribed to the growth-induced one because its magnitude is reduced by annealing. The sign of the growth-induced birefringence is positive (n

T
M
-n

T
E
>0), and it is favorable to achieve complete TE-TM mode conversion.
Electrochemical Hydrogen-Storage in Ti–Mn Alloy Electrodes
Authors: Yayama Hideki , Ichinomiya Osamu , Hirakawa Kazuyoshi
Published: November 2005

The structure of new hydrogen storage electrodes, consisting of TiMn
x
(x=0.5∼1.75) and a binder, and their electrochemical properties are described. Powdered Ti–Mn alloys were sintered with Ni powder used as a binder. When the electrode potential is higher than –1.075 V vs. Ag/AgCl, Ni is inactive and does not take part in the electrode reaction. The electrodes can be activated by repeating about 10 cycles of cathodic and anodic elecrolysis. The amount of absorbed hydrogen increases with decrease of Mn content. Because of the large current capacity, Ti–Mn promises to be an excellent elecrode for a battery with high energy density.
Influence of Substrate Temperature on the Growth of AlGaAs/GaAs Quantum Well Heterostructures by Organometallic Vapor Phase Epitaxy
Authors: Shealy J. R. , Wicks G. W. , Ohno Hideo , Eastman L. F.
Published: November 2005

The growth of AlGaAs/GaAs quantum well heterostructures by organometallic vapor phase epitaxy has been investigated over a range of substrate temperature from 500°C to 700°C. Low temperature photoluminescence from single quantum wells less than 150Å in width has been observed at low excitation levels. Evidence of a graded heterostructure interface was observed in samples grown at higher substrate temperatures.
GaAs and GaAlAs Equi-Rate Etching Using a New Reactive Ion Beam Etching System
Authors: Asakawa Kiyoshi , Sugata Sumio
Published: November 2005

GaAs and GaAlAs equi-rate etchings, which are difficult in the conventional reactive ion etching (RIE), have been achieved by using Cl2 plasma flux in a new reactive ion beam etching (RIBE) system. The system has an ultra-high-vacuum (UHV) design basis and several plasma monitors for investigating an elementary etching process. The establishment of the equi-rate etching has been presumed as due to the possible elimination of particles contributing to the aluminum-oxide or other non-volatile material formation, such as C, O2 and H2O.
High Resolution Double Layer Resist System Using New Silicone Based Negative Resist (SNR)
Authors: Morita Masao , Tanaka Akinobu , Imamura Saburo , Tamamura Toshiaki , Kogure Osamu
Published: November 2005

We propose a new silicone based negative resist (SNR) for a high resolution double layer resist system. SNR shows high sensitivity to an e-beam, D0.5=5 µC/cm2, with high contrast γ=2, and excellent resistance to reactive ion etching under oxygen gas. A submicron pattern with a high aspect ratio can be easily fabricated with the SNR/AZ double layer resist system. It is also shown that submicron lithography can be accomplished on a substrate with topographic features.
Composition Deviation and Its Effect on Lattice Constant in Pseudoquaternary Compound Alloy System
Authors: Sonomura Hajimu , Horinaka Hiromichi , Miyauchi Takeshi
Published: November 2005

A quaternary alloy usually espressed in the formula A
x
B1-x
C
y
D1-y
is actually a pseudoquaternary alloy of the four binary compounds, so that the alloy should be presented as (AC)α(AD)β(BC)γ(BD)δ. Even if x and y are given, the fractions of the constituent compounds α, β, γ and δ, however, cannot be fixed on the specified values; those are permitted a somewhat extended range. It is shown that the lattice matching condition of LPE of a quaternary alloy to a substrate is not rigid in the relation of x and y as generally considered, but can be pliable to some extent.
Characteristics of Be–Si–Au Ternary Alloy Liquid Metal Ion Sources
Authors: Gamo Kenji , Matsui Takao , Namba Susumu
Published: November 2005

Be-Si-Au ternary alloy liquid metal ion sources have been fabricated and basic characteristics such as mass spectra, energy distribution and angular current intensity have been measured. It was observed that for Be and Si, doubly charged ions are dominant over singly charged ions and the angular current intensity for the doubly charged ions is about 20 and 11 µA/str for Be and Si, respectively, at an energy spread (FWHM) of 10 eV. The present ion source could be operated for about 100 hours and is important for maskless implantation of both p- and n-type dopants in GaAs.
Compact Toroids with Rotating Halo-the Spintor
Authors: Ikuta Kazunari
Published: November 2005

Stability analysis to tilting mode is performed for a type of compact toroids (CT) spinning about its axis of symmetry and a new method of giving CT a spin about the axis is proposed.
Coherent Anti-Stokes Raman Spectroscopic Study of CO2 Laser CVD of Silane
Authors: Hanabusa Mitsugu , Kikuchi Hiroshi
Published: November 2005

Coherent anti-Stokes Raman spectroscopy (CARS) has been used to study gas phase processes involved in CO2 laser chemical vapor deposition of silane. SiH4 CARS spectrum exhibited a unique profile which was interpreted as arising from excitation of rotational levels following gas phase reactions. From N2 CARS thermometry, the CO2 laser beam was found to raise the temperature of the gas containing silane. Using the observed CARS results, we discuss why silicon films are deposited faster when the CO2 laser is tuned to absorption lines of silane.
InGaAsP/InP Mushroom Stripe Lasers with Low CW Threshold and High Output Power
Authors: Burkhard H. , Kuphal E.
Published: November 2005

We report on InGaAsP/InP mushroom stripe lasers, for which a technique has been developed to precisely control the width of the active layer. Both p-substrate upside up mounted and n-substrate upside down mounted devices were fabricated. The lasers emit at λ=1.3 µm having a CW threshold as low as 18 mA, an external differential efficiency of up to 0.30 W/A at 200°C and a characteristic temperature T
0=65 K. An output CW power in the fundamental transverse mode of 18 mW/mirror was obtained for upside up mounting. A 960 Mbit/sec RZ modulation is demonstrated.
Preparation and Some Properties of Highly Resistive a-Si:H:F Film
Authors: Nakayama Yoshikazu , Akiyama Koji , Kawamura Takao
Published: November 2005

Highly resistive a-Si:H:F film more than 1014 Ωcm at room temperature is prepared by a glow discharge in a gas mixture of SiF4, SiH4 and H2 under the condition of suppressing the formation of SiF3 bonds. The film shows an excellent conductivity change of 4 orders of magnitude at illumination with light 650 nm in wavelength and 50 µW/cm2 in intensity. It is also described that the formation of SiF3 bonds, which becomes remarkable at lower total gas-flow rate as well as higher partial flow rate of SiF4, leads to the degradation of electric properties such as decrease of dark resistivity, photoconductivity and drift mobility.
Semiconductor Field Ion Micrographs
Authors: Sakurai Toshio , Sakata Toyo , Jimbo Akiko
Published: November 2005

Using commercially available wafers, imaging of various semiconductor surfaces was attempted by field ion microscopy (FIM). High quality images were obtained for Si, Ge, GaAs and GaP.
Relaxation Oscillation in Transient Output of Pulsed CO2 Laser
Authors: Ueda Kenichi , Shimizu Fumiko O.
Published: November 2005

A periodic undulation was observed in the output of a 10.6 µm CO2 laser in the afterglow region of the pulsed discharge, while no undulation appeared in the output of a 9.6 µm CO2 laser under any of the experimental conditions studied. It is shown that the observed undulation is due to the relaxation oscillation and occurs in the balance between the rate of induced emission from the upper laser level and the rate of relaxation from the lower laser level.
The rate equations for the model of the lasing system give the solution of the relaxation oscillation, even when the continuous pumping to the upper laser level is absent but the fast relaxation from the lower laser level is present. The calculations give a good description of the characteristics of the undulation, which depends on the partial pressures of the constituent gases. The relaxation rate constant relevant to the lower laser level (100) was determined from the analysis as ∼4.2×103/(Torr·s) (CO2–He). This agrees well with values previously obtained by the infrared pulsegain method.
ESR Study of Irradiated Pb(NO3)2
Authors: Tagaya Kimihito , Kitagawa Michiharu
Published: November 2005

Single crystals of Pb(NO3)2 were irradiated with X or γ-rays at room temperature, and ESR measurements were performed over the temperature range from 85 K to room temperature. It was concluded that besides O2
- , O3
- and NO2 centers, F-centers were produced, in which an electron was trapped by an NO3
- vacancy. The orientations of F and NO2 centers in a Pb (NO3)2 crystal were determined from the principal directions of the g or hyperfine tensor. The superhyperfine interactions of F and O2
- centers with adjacent 207Pb and 14N nuclei were also investigated, and the spin-density distributions on these atoms were estimated.
Selectively-Doped GaAs/n-AlGaAs Heterostructures Grown by MOCVD
Authors: Kobayashi Naoki , Fukui Takashi , Tsubaki Kotaro
Published: November 2005

Selectively-doped GaAs/n-Al0.3Ga0.7As heterostructures were grown by reduced-pressure metalorganic chemical vapor deposition. It is shown that the growth conditions in an undoped Al0.3Ga0.7As spacer layer have a remarkable effect on the two-dimensional electron gas (2DEG) mobility. A 2DEG mobility of 150000 cm2/V·s is obtained for a sheet electron concentration (N
s) of 6.9×1011 cm-2 at 4.2 K. The 2DEG mobility increases with incrasing N
s as a result of exposure to light and reaches a maximum value of 180000 cm2/V·s at N
s=7.8×1011 cm-2.