bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanometer Pattern Delineation by Electron and Ion Beam Lithography
Authors: Gamo Kenji , Yamashita Kazuhiro , Namba Susumu
Published: November 2005

Nanometer pattern delineation techniques have been investigated using electron and ion beam lithography. About a 20 nm wide resist and Au pattern was formed by 40 keV electron beam exposure and a lift-off technique. For ion beam lithography, about 60 nm wide patterns were formed by 50 keV H+ exposure and by using a thin carbon membrane mask. It was confirmed that a H+ beam exposure gives a very high contrast ratio and a high resolution patterning.
Effect of Oxygen Adsorption on the Ion-Induced Auger Electron Spectra of Mg and Al
Authors: Saiki Koichiro , Tanaka Shoji
Published: November 2005

Ion-induced Auger electron spectra of Mg and Al were investigated under various oxygen partial pressures. Some peaks reduced their intensities as the oxygen patial pressure increased, while other peaks showed only a slight decrease. The feature of the Auger peaks seems to correlate with the charge state of the excited atoms emitting Auger electrons. The results proved to be useful for the assignment of Auger transitions.
Effects of Insulated Gate on Ion Implanted InSb p+n Junctions
Authors: Fujisada Hiroyuki , Sasase Takafumi
Published: November 2005

Current-voltage characteristics for Be ion implanted InSb p+n junctions with insulated gate fabricated by planar technology are studied. It has been demonstrated by field effects of the insulated gate that a large current can be originated from the surface of the p+ region. Results also suggest that the insulated gate is a good way to improve properties of the p+n junction and a low dose of 4.1×1012 cm-2 at 90 keV is enough for preparation of a good p+n junction.
Electromagnetic Coupling Effects in BaPb0.7Bi0.3O3 Two-Dimensional Josephson Tunnel Junction Arrays
Authors: Moriwaki Kazuyuki , Suzuki Minoru , Murakami Toshiaki
Published: November 2005

Electromagnetic coupling effects where remarkable voltage generation was observed have been evidenced between two-dimensional Josephson-junction arrays in BaPb0.7Bi0.3O3 sputtered films with an intermediate Al2O3 insulation layer. The results indicate that the coherent state is realized and the array becomes superradiative.
Substrate Temperature Dependence of Electron Drift Mobility in Glow-Discharged Hydrogenated Amorphous Silicon
Authors: Shirafuji Junji , Kuwagaki Mamoru , Inuishi Yoshio
Published: November 2005

The substrate temperature dependence of the electron drift mobility and lifetime in glow-discharged a-Si: H films has been measured. The room temperature electron mobility increases nearly exponentially with increasing substrate temperature. The temperature dependence of the electron mobility reveals that the activation energy of the mobility decreases slightly with increasing substrate temperature. Results are discussed in terms of the conduction band tail width or micro-crystalline formation. The electron lifetime depends also on the substrate temperature in a different manner from the electron mobility and has a maximum near 200°C.
Application of Abrupt and Graded Gap Structure in High Speed Semiconductor Devices
Authors: Chiu L. C. , Kao C. K.
Published: November 2005

A comparison of the speed performance of abrupt and graded gap semiconductor structures is described. It is found that appropriately designed abrupt structure offers superior performance than the graded structure.
Measurement of Electron Mobility in Hydrogenated Amorphous-Silicon Using 4-Terminal Transistor Structures
Authors: Uchida Yasutaka , Matsumura Masakiyo
Published: November 2005

Field dependence of field-effect mobility in hydrogenated amorphous-silicon has been investigated using a novel 4-terminal transistor structure. The mobility evaluated from the transistor characteristics did not depend on electric field strength up to 20 kV/cm.
Development of High Resolution ESR Imaging to Investigate on Paramagnetic Species in Thin Film Samples
Authors: Ohno Keiichi
Published: November 2005

A high resolution ESR imaging was constructed to measure microscopic spatial distribution of paramagnetic species. The spatial resolution of about 20 µm was attained for a stable radical diphenylpicorylhydrazyl (DPPH). The maximum magnetic field gradient of about 1200 gauss/cm was obtained by feeding pulsed DC current (maximum peak current is 30 Å) into a Helmholtz coils pair equipped with a rectangular mode microwave X-band cavity. The orientation distribution of directors was measured in a thin flat cell (thickness 500 µm) of a nematic liquid crystal MBBA.
Improvement of the Superconducting Magnetic Levitation System for an Absolute Determination of the Magnetic Flux Quantum
Authors: Shiota Fuyuhiko , Hara Ko , Hirata Takaaki
Published: November 2005

The superconducting magnetic levitation system for the absolute determination of the magnetic flux quantum φ0 is improved. Resolution of the vertical position of the floating body with laser interferometer becomes 1/100 µm order, which corresponds to 1 ppm of the gravitational potential energy of the floating body. An outline of this system and some temporary results are described.
Preparation of sp3-Rich Amorphous Carbon Film by Hydrogen Gas Reactive RF-Sputtering of Graphite, and Its Properties
Authors: Miyasato Tatsuro , Kawakami Youichi , Kawano Toshifumi , Hiraki Akio
Published: November 2005

An a-C:H film was prepared for the first time by H2 gas reactive rf-sputtering of a graphite target onto low temperature (room temperature ∼150°C) substrate. This film has a uniform amorphous structure and an H-atom ratio of 0.8 H/C; its electrical resistivity was 106∼1012 Ωcm. Vickers' hardness number of the film was 1000∼2000. IR, Raman and ESCA spectra showed that the bonding between the neighbouring C-atoms was for the most part by sp3 bond, and that sp2 bond was rare. Approximately 200 Å of diamond grains were observed by TEM in annealed film at 1000°C, and verified by electron diffraction pattern.
Surface Stress in a Preform of Polarization-Holding Fiber Having Isolated Stress-Producing Lobes
Authors: Shibata Nori , Tokuda Masamitsu
Published: November 2005

Stress profile at the surface of a polarization-holding fiber preform having isolated stress-producing lobes was measured by a quarter-wave plate method. It was experimentally and theoretically verified that the surface stress was compressive anywhere along the circumference of the preform. The results of tensile tests carried out on the fiber, which was drawn from the preform, showed strength well comparable to that of ordinary optical fibers having no stress-producing lobes.
Ellipsometry and Reflectance of Etched (100) Surfaces of Undoped, Semi-Insulating LEC GaAs
Authors: Hoshino Takashi , Moritani Akihiro , Nakai Junkichi
Published: November 2005

It is demonstrated that ellipsometry combined with reflectance measurement provides useful information on the distribution of each pits due to crystal defects on the (100) surface of undoped, semi-insulating LEC GaAs etched with molten KOH.
Cavity-Type Target and Its Scaling Law in Laser-Driven Fusion
Authors: Nishiguchi Akio , Yabe Takashi
Published: November 2005

This letter presents one-dimensional simulation results on a cavity-type target in a GEKKO XII laser parameter range. A simplified model is given to illustrate the implosion process. For a thin inner shell, ram pressure dominates the process, but for a thick inner shell, static pressure and radiation effect dominate. Comparison of the model and the simulation results clearly classifies the implosion process into three modes.
Moisture Induced Failures in Plastic Encapsulated 64 kbit Dynamic RAM's
Authors: Satoh Yoshihiro , Iwamori Kiyoshi , Sawada Kokichi , Miyamoto Kazutoshi , Matsumoto Heihachi
Published: November 2005

The moisture induced aluminum corrosion in practical 64 kbit dynamic RAM's is described. In the unimproved RAM's, moisture induced failures are composed of two Weibull-distributions, that is, the random failures of short lifetime and the wear-out failures of long lifetime. Improvement of the passivation films reduced the random failures dramatically. The instantaneous failure rate of the improved RAM's is estimated to be less than 24 FIT throughout 10 years of operation at 40°C/60%.
Highly Conductive and Transparent Aluminum Doped Zinc Oxide Thin Films Prepared by RF Magnetron Sputtering
Authors: Minami Tadatsugu , Nanto Hidehito , Takata Shinzo
Published: November 2005

Highly conductive films of Al-doped ZnO have been prepared by rf magnetron sputtering of a ZnO target with Al2O3 dopant of 1–2 wt% in content added. Films with resistivity as low as 2×10-4 Ωcm and transmittance above 80% at the wavelength between 400 and 800 nm can be produced on low temperature substrate with a relatively high deposition rate. It is shown that a stable resistivity for use in various ambients at high temperature can be attained for the films. The characteristic features of Al-doped ZnO films are their high carrier concentration and low mobility in comparison with non-doped ZnO films.
Alloy Fluctuation in Mixed Compound Semiconductors as Studied by Deep Level Transient Spectroscopy
Authors: Yoshino Junji , Tachikawa Masami , Matsuda Naotoshi , Mizuta Masashi , Kukimoto Hiroshi
Published: November 2005

Deep level transient spectroscopy (DLTS) has been utilized to detect alloy fluctuation around defects in several kinds of alloy semiconductors. An increased half-width in the DLTS spectrum has been observed in the ternary and quaternary systems of InGaP and InGaAsP whereas the binary systems of GaP and InP have not shown such broadening. The broadening can be interpreted as a fluctuation of defect properties due to the increased freedom of atom arrangements around the relevant defect in the alloy systems.
Gallium Arsenide Layers Grown by Molecular Beam Epitaxy on Single Crystalline Germanium Islands on Insulator
Authors: Takai Mikio , Tanigawa Takaho , Minamisono Tadanori , Gamo Kenji , Namba Susumu
Published: November 2005

Gallium arsenide (GaAs) layers have successfully been grown by molecular beam epitaxy on single crystalline germanium (Ge) islands, recrystallized by zone melting with SiO2 capping layers, on thermally-oxidized Si-wafers. The GaAs layers, grown on the single crystalline Ge islands, show smooth surfaces without any grain-boundaries, while those, grown on the Ge islands with grain-boundaries and on the SiO2, have grain-boundaries. The GaAs layers on the single crystalline Ge islands emit photoluminescence, the intensity of which is almost comparable to that of GaAs layers on bulk Ge crystals.
Tunneling Hot Electron Transistor Using GaAs/AlGaAs Heterojunctions
Authors: Yokoyama Naoki , Imamura Kenichi , Ohshima Toshio , Nishi Hidetoshi , Muto Shunichi , Kondo Kazuhiro , Hiyamizu Satoshi
Published: November 2005

The first tunneling hot electron transistor (HET) using semiconductor heterojunctions has been achieved. This device uses GaAs/AlGaAs heterojunctions grown by molecular beam epitaxy and sophisticated process technology. Transfer efficiency for hot electrons through 100 nm thick n-GaAs was measured as 0.28.
Effect of Metals Used for Schottky Barrier Contacts on DLTS Signals for LEC n-GaAs Crystals
Authors: Yahata Akihiro , Nakajima Masato
Published: November 2005

DLTS signals for midgap electron traps in LEC n-GaAs crystals were found to depend on the species of metals used for Schottky barrier contacts, aluminum and gold, and to change by annealing. SIMS analyses suggested that interfacial reaction between the contact metals and semiconductors was responsible for the change of the DLTS signals.
Superconductivity in Lithium Intercalated 1T– and 4Hb–TaS2
Authors: Nozuyama Yasuyuki , Iida Shuichi
Published: November 2005

Lithium intercalated single crystals of 1T– and 4Hb–TaS2 were obtained by keeping the crystals in a hexane solution of n-butyllithium at 60∼80°C for 1∼2 weeks. The electrical resistivities showed that they are metallic and become superconductive below 4.57 K and 4.33 K, respectively.
Tunneling Measurements on A15 Nb–Si Films
Authors: Asano Hidefumi , Nakamura Kiko , Maeda Yasushi , Michikami Osamu
Published: November 2005

Tunnel junctions have been fabricated on A15 Nb–Si (19–21 at.% Si) films prepared by a dual-target dc-magnetron sputtering method. Nb–Si/oxide/Pb junctions with good tunneling characteristics were obtained using a CF4 cleaning process, in which the Nb–Si base electrode surface was sputter-cleaned in an Ar+CF4 gas mixture prior to oxide barrier formation. Tunneling measurements indicate that Nb-rich A15 Nb–Si is a weak-coupling superconductor, as the same as Nb-rich A15 Nb–Ge and Nb–Al.
Development of Phosphorus Liquid-Metal-Ion Source
Authors: Ishitani Tohru , Umemura Kaoru , Tamura Hifumi
Published: November 2005

A phosphorus liquid-metal-ion source that uses a Cu–P alloy as its source material is described. The P+ ion emission current is about 10% of total emission current, which consists mainly of Cu+ ions. Energy spread of P+ ions is 25 eV at a total current of 30 µA, while that of Cu+ is 28 eV. A source lifetime of more than 20 hours is achieved at a total current of 50–60 µA.
Determination of Impurity Distribution in p-Type Si Epitaxial Layers by C-V Analysis of Sm on p-Type Si Schottky Diodes
Authors: Miki Katsuhiko , Yoshida Naosato
Published: November 2005

Schottky diodes were formed on p-type Si by evaporating Sm in a vacuum. Impurity concentration determined by the C-V analysis of the Schottky diodes coincided quite well with that calculated from four-point resistivity, making this method suitable for accurately measuring the impurity distribution in p-type epitaxial layers.
Effects of Whole Ingot Annealing on 1.49 eV PL Properties in LEC-Grown Semi-Insulating GaAs
Authors: Yokogawa Masamichi , Nishine Shiro , Sasaki Masami , Matsumoto Kazuhisa , Fujita Keiichiro , Akai Shin-ichi
Published: November 2005

The effects of whole ingot annealing on 1.49 eV photoluminescence (PL) properties at 4.2 K in undoped/low-Cr doped LEC-grown semi-insulating GaAs have been studied. It has been found that whole ingot annealing considerably increases the PL intensities with no significant degradation of semi-insulating properties. It has been also found that whole ingot annealing drastically reduces both the radial variation of PL intensity distribution and the difference of PL intensities between seed end and tail end.
Ultra-Fine Spherical Particles of γ-Alumina: Electron Microscopy of Crystal Structure and Surface Morphology at Atomic Resolution
Authors: Iijima Sumio
Published: November 2005

The γ-alumina particles are produced by a dry method developed by the author. Three types of structures, tentatively called δ' (orthorhombic; Pmn21; a=8.2, b=16.4, c=11.8 Å), θ1 (monoclinic; B2/b; a=11.1, b=12.1, c=17.7 Å, β=103° ) and θ2 (monoclinic, B2/m; a=11.1, b=12.1, c=2.9 Å, β=103°) are found. The particle is spherical but facetted with flat {111} and {100} surfaces; {110} surfaces consist of many small {111} facets. As a new approach to ceramics and catalysis research, surface morphology of a neck portion of two coalescing particles, and clusters of Rh6(CO)16 impregnated on the particles are demonstrated for the first time.
Comment on Polarization Dependent Momentum Matrix Elements in Quantum Well Lasers
Authors: Yamanishi Masamichi , Suemune Ikuo
Published: November 2005

The polarization dependent gain in quantum well lasers reported previously is explained theoretically in terms of the polarization dependence of momentum matrix elements related to conduction-to-heavy hole and conduction-to-light hole band transitions.
Measurement of Minority Carrier Lifetimes using AC Photovoltages Excited by Two Photon Beams of Different Wavelengths
Authors: Honma Noriaki , Munakata Chusuke , Itoh Haruo
Published: November 2005

Results of using two chopped photon beams with wavelengths of 1.15 and 0.6328 µm, to measure the ac surface photovoltages of a Si wafer and a bar while changing the chopping frequency are presented. The ratio of ac surface photovoltages with 1.15 µm to that with 0.6328 µm vs frequency represents the frequency dependence of the photocurrent. From the frequency at the knee point that appears on the frequency dependence curve of the ratio, the lifetimes for minority carriers in a Si wafer and a bar are obtained. The observed values of 9.65 µs and 86 µs agree well with the 9.7 µs and 90 µs obtained by conventional methods.
Direct Comparison of Fine Structure on Ti L3 Threshold by Disappearance Potential and Auger Electron and Soft X-Ray Appearance Potential Spectroscopies
Authors: Nishimori Katsumi , Tokutaka Heizo , Kohno Masahiro , Ishihara Naganori
Published: November 2005

We have investigated the fine structure on Ti L3 threshold of clean polycrystalline Ti surface by three spectroscopies. The Ti L3 soft X-ray appearance potential spectrum was subtracted from the disappearance potential spectrum. The difference spectrum shows a surface local density of states above Fermi level. The result is in good agreement with the calculation for the first layer of Ti(0001) thin film.
Free Carrier Profile Synthesis in MOCVD Grown GaAs by `Atomic-Plane' Doping
Authors: Ohno Hideo , Ikeda Eiji , Hasegawa Hideki
Published: November 2005

Synthesis of free carrier profiles in GaAs by metalorganic chemical vapor deposition is realized by `atomic-plane' doping, in which growth is suspended while doping gas is introduced. Silicon, which stays on the surface even without GaAs growth, is used as a dopant for the `atomic-plane' doping.
Homogeneous Dopant Distribution of Silicon Crystal Grown by Vertical Magnetic Field-Applied Czochralski Method
Authors: Hoshikawa Keigo , Kohda Hiroki , Hirata Hiroshi
Published: November 2005

Phosphorus-doped Czochralski (CZ) silicon crystals with less than 5% macroscopic radial and microscopic axial resistivity variations are grown in the presence of 1000 Oe vertical magnetic field strength. Crystals with extremely improved dopant homogeneity are facilitated by determining the appropriate crystal and crucible rotation rates corresponding to the residual thermal convection in the molten silicon. Experimental results can be consistently explained by flow model of forced and thermal convections which are stabilized by a magnetic field.
Local Loading Effect in Selective Silicon Epitaxy
Authors: Ishitani Akihiko , Endo Nobuhiro , Tsuya Hideki
Published: November 2005

In selective epitaxy, growth rate is modified by the ratio of unmasked area to entire surface area and by each window area on a wafer. Such “local loading effect” phenomena were studied in a SiH2Cl2/HCl/H2 selective epitaxial growth system. The effect is attributed to species spatial concentration variation which is generated by coexistence of a masked area and windows on a wafer. The growth condition which can suppress the effect is obtained for VLSI device fabrication.
Deep-Level Luminescence of Cr-Doped GaAsP Alloys
Authors: Fujiwara Yasufumi , Kojima Atsushi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

Deep-level photoluminescence spectra of Cr-doped GaAsP alloys have been measured systematically over the whole composition range. It has been found that the Cr-related luminescence spectra of GaAs1-x
P
x
:Cr alloys exhibit only a broad band without the well-known characteristic sharp zero-phonon line as in GaAs and GaP, and the peak position is nearly unchanged with respect to the alloy composition below the phosphorus composition of x∼0.65. Moreover the halfwidth of the Cr-related band is larger in GaAsP than in GaAs and GaP. Luminescence-excitation data indicate that the below-gap excitation is dominant in GaAsP alloys.
Tunable Near-Infrared Picosecond Pulses from a Mode-Locked Dye Laser Synchronously Pumped by Second Harmonic of a Nd:YAG Laser
Authors: Kobayashi Hiroshi , Tanaka Shosaku , Watanabe Akira , Kuwata Takaaki , Tabuchi Haruhiko , Ueoka Mitsuo
Published: November 2005

Tunable near-infrared picosecond pulses with ∼25 ps duration and ∼10 MW peak power are produced by a mode-locked dye laser synchronously pumped by second harmonic train from a passively mode-locked Nd:YAG laser. The lasing wavelength can be tuned from 720 to 830 nm using several polymethine dyes. It is found that the most important characteristic for picosecond lasing dye is a fast rise of an amplified spontaneous emission rather than higher fluorescence efficiency.
Characteristics of Ion Beam Assisted Etching of GaAs Using Focused Ion Beam: Dependence on Gas Pressure
Authors: Ochiai Yukinori , Gamo Kenji , Namba Susumu
Published: November 2005

Characteristics of maskless ion beam assisted etching of GaAs have been investigated. A focused Ga beam was irradiated on GaAs in a chlorine atmosphere. It was observed that this etching technique gives a higher etching rate than physical sputter etching without chlorine gas. The etching rate exhibited a maximum at a gas pressure of about 20 mTorr and decreased above that. By the present technique, 0.3 µm wide, 3 µm deep U-shaped grooves were formed on GaAs surface, while by physical sputter etching the grooves were V-shaped and narrow due to redeposition and/or self focusing effect.
High Dose Rate Effect of Focused-Ion-Beam Boron Implantation into Silicon
Authors: Tamura Masao , Shukuri Shoji , Ishitani Tohru , Ichikawa Masakazu , Doi Takahisa
Published: November 2005

The effect of high-dose-rate, 16 keV focused-ion-beam (FIB) B+ implantation into Si has been investigated as a function of current density and beam-scan speed. It is shown by µ-RHEED (micro-probe reflection high-energy electron diffraction) observation that the increase in electrical activation of implanted B atoms at such low temperature annealing as 600°C closely correlated with the increase in amorphous zones produced. It is also found that continuous amorphous layer formation occurs with a 1–2×1015 ions/cm2 (one order lower than for conventional implantation) when both implantation conditions of high current density and slow scan speed (e.g. 20 mA/cm2 and 6×10-3 cm/s) are satisfied. The reason for amorphous zone formation enhancement by FIB implantation is discussed.
Growth of High-Quality ZnSe Films by Low-Pressure Metalorganic Chemical Vapor Deposition
Authors: Yoshikawa Akihiko , Tanaka Keiji , Yamaga Shigeki , Kasai Haruo
Published: November 2005

Effects of growth conditions, especially substrate temperature, on the electrical and photoluminescence properties of nominally undoped ZnSe films grown on GaAs substrates by low-pressure MOCVD have been studied. It has been shown that the substrate temperature remarkably affects the electrical and photoluminescence characteristics of films. It was found that high conductivity ZnSe films can be grown without intentional doping, and that high-quality ZnSe films involving low-concentration electron-scattering centers and exhibiting a strong blue near-band-edge emission can be grown.
Growth and Resistivity Characteristics of Undoped Semi-Insulating GaAs Crystals with Low Dislocation Density
Authors: Shimada Takashi , Obokata Takeshi , Fukuda Tsuguo
Published: November 2005

Remarkably low dislocation density of approximately 1000/cm2 (minimum 600/cm2) and uniform distribution were attained in two inch diameter undoped GaAs single crystals grown by an improved LEC technique. Resistivity was revealed to be high enough (1×108 Ω·cm) and homogeneity was remarkably improved over that of conventional high dislocation density LEC crystal.
Evaluation of InSb MOS Structure with Thin Anodic Oxide
Authors: Fujisada Hiroyuki , Sasase Takafumi
Published: November 2005

Interface and electrical properties of thin anodic oxide of InSb with a thickness of 330 Å are described. The thin anodic oxide has about one order of magnitude smaller interface state densities than thick anodic oxide. Electrical insulation is excellent at 77 K and even at room temperature. A flat band voltage shift of C-V curve is small for the maximum fabrication process temperature of 120°C and drastically increases even for annealing in H2 gas at 200°C.
AlSb–GaSb and AlAs–GaAs Monolayer Superlattices Grown by Molecular Beam Epitaxy
Authors: Hirayama Yoshiro , Ohmori Yutaka , Okamoto Hiroshi
Published: November 2005

In this paper we report the synthesis and properties of AlSb–GaSb and AlAs–GaAs monolayer superlattices grown by molecular beam epitaxy. The ordering in the monolayer superlattices is confirmed by an X-ray diffraction technique. The photoluminescence intensity from monolayer superlattice is stronger than that from mixed crystals with the same Al molar odicity in structure of ML-SL is confirmed by X-ray
Current Drift Phenomena and Spectroscopic Measurement Method for Insulator Trap Level Parameters in InP MISFETs
Authors: Yamaguchi Eiichi , Minakata Makoto , Furukawa Yoshitaka
Published: November 2005

A general formula has been developed for the transient response of drain current in inversion-mode InP MISFETs on the basis of a tunneling injection model. A spectroscopic measurement method has been found for determining parameters of insulator trap states which cause the current drift. The method has then been applied to an InP MISFET with a gate insulator BN. Further, the tunneling injection effect on hysteresis in capacitance-voltage characteristics has been discussed in InP MIS structures.
Deposition of Phosphorus Doped Silicon Films by Thermal Decomposition of Disilane
Authors: Nakayama Satoshi , Yonezawa Hiroki , Murota Junichi
Published: November 2005

Phosphorus doped silicon films are deposited in the temperature range 520–665°C by thermal decomposition of Si2H6. It is found that (i) the deposition rate is not decreased by the addition of PH3 in contrast with the deposition rate for the SiH4 system and is about 100 times higher than that for the SiH4 system for phosphorus concentration above 1×1020 cm-3, (ii) phosphorus concentration is proportional to the PH3 partial pressure and to the –3/2 power of Si2H6 partial pressure. These characteristics mean that Si2H6 is suitable as a source gas to prepare the heavily phosphorus doped polycrystalline silicon for fabricating gate or emitter electrodes of LSI's.
Influence of Transmission Resonance on Current-Voltage Characteristics of Semiconductor Diodes including a Quantum Well
Authors: Zohta Yasuhito
Published: November 2005

In small semiconductor devices, electrons show a wave property. Electrons coming to a quantum well are partly reflected and partly transmitted at the well. The electron motion in semiconductor diodes including the quantum well is studied. Under conditions where the energy of the electrons coming to the quantum well can be controlled by an external field, current-voltage characteristics of the diodes are calculated. Preliminary results show anomalous current-voltage characteristics and the possibility of a negative resistance due to transmission resonance.
Measurement of Spatial Distribution of Transport-Photocarriers in Amorphous Chalcogenide
Authors: Imamura Shunji , Kitamura Takashi , Nakamura Naomasa
Published: November 2005

A method for measuring the spatial distribution of photocarriers which are transported in amorphous chalcogenide is reported. The specimen is a double-layer system composed of an amorphous chalcogenide and another material with even higher mobility. The density of carriers at the interface between the two layers is estimated from the induced photocurrent in the time-of-flight measurement. Then, the spatial distribution can be determined by a combination of these values for the chalcogenides with different layer thicknesses. The experimental results for As2Se98 and As2Se3 agree well with the theoretical predictions.
Kinetic Analysis of Pressure-Induced Phase Transition by Means of Raman Scattering
Authors: Takano Kaoru J. , Wakatsuki Masao
Published: November 2005

A kinetic analysis of a pressure-induced phase transition in solid was attempted by repeatedly measuring peak intensities of Raman bands of HgI2 with a period of 30 milliseconds during the phase transition which was induced by a pressure jump and driven at a constant pressure in a diamond anvil cell. The analysis was made on the assumption that the degree of transformation was proportional to the peak intensity corresponding to the phase formed. The results show that the higher the excess pressure the faster the transition proceeds, and are well fitted to the Avrami equation.
In Situ Observation on Melt Growth Process of Tin Crystal by Means of Synchrotron X-Ray Topography
Authors: Nittono Osamu , Ogawa Taro , Gong Sheng Kai , Nagakura Sigemaro
Published: November 2005

Melting and growth processes of a thin Sn crystal with low dislocation density have been investigated using synchrotron radiation and a TV imaging system. When the melting rate is less than 2.7 mm/min, the melting interface follows a circular equal-melting point interface and appears to be homogeneously smooth. No facet growth is seen at a growth rate of 2.3 mm/min. Most of the dislocations do not propagate into a newly grown crystal and the homogeneous solidification results in a nearly perfect crystal. Dislocations and slip bands were found to generate from a part where the solidification was completed.
Doping of Poly-p-Phenylenesulfide (PPS) with AlCl3, FeCl3 and TaF5
Authors: Tsukamoto Jun , Matsumura Kiichiro
Published: November 2005

Poly-p-phenylene sulfide (PPS) can be doped rapidly with AlCl3, FeCl3 and TaF5 from solution to give electrically conductive (3.0×10-1 S/cm, 3.4×10-3 S/cm, and 6.5×10-2 S/cm, respectively) polymers. Using these dopants, the effect of morphology in starting polymers on the doping process was investigated. The results from doping of PPS with different crystallinity suggest that doping proceeds in the amorphous region in PPS.
MOCVD Growth and Characterization of (AlxGa1-x)yIn1-yP/GaAs
Authors: Ban Yuzaburoh , Ogura Mototsugu , Morisaki Motoji , Hase Nobuyasu
Published: November 2005

We have demonstrated the MOCVD growth of AlGaInP under low pressure using a self-cracking system (SCS) for the group V hydride (PH3). In InGaP growth, the incorporation efficiency of In atoms for the SCS method is higher than that for the conventional method. For AlInP growth, however, efficiency did not depend on growth methods or growth temperatures. The compositions of AlGaInP are independent of PH3 flow rates and growth temperatures. These results indicate that it is easy to control the alloy compositions of the AlGaInP/GaAs system using the SCS method, even though growth conditions fluctuate slightly.
A New Highly-Conductive (AlGa)As/GaAs/(AlGa)As Selectively-Doped Double-Heterojunction Field-Effect Transistor (SD-DH-FET)
Authors: Inoue Kaoru , Sakaki Hiroyuki
Published: November 2005

A new type of field-effect transistor (SD-DH-FET) has been successfully fabricated in which very-high-density electrons (∼1.27×1012/cm2) are supplied from a selectively-doped (AlGa)As/GaAs/(AlGa)As double-heterojunction structure grown by molecular beam epitaxy. The structure showed an extremely high sheet conductivity of 24 mS/□ at 77 K with a Hall mobility of 119,000 cm2/Vs. A depletion-mode FET with this structure showed high channel mobility of more than 35,000 cm2/Vs at 77 K, suggesting that SD-DH-FETs have potential for applications to extremely high-speed microwave devices and integrated circuits.
Fluxon Feedback Oscillator
Authors: Sakai Shigeki , Akoh Hiroshi , Hayakawa Hisao
Published: November 2005

A fluxon feedback oscillator which is formed by a ring-like Josephson transmission line with a feedback resistor is proposed. A device with a Josephson transmission line made by the NbN/NbN junction is fabricated, and the successful operation of the device is obtained using the Josephson sampler. The oscillation period can be controlled between 35 and 70 ps. The results agree well with simulation results. Possible applications of the fluxon feedback oscillator are also discussed.
Liquid-Phase Epitaxial Growth of ZnSe Using Sb0.4Se0.6 as Solvent
Authors: Nakamura Hiroshi , Kojima Seiji , Washiyama Masako , Aoki Masaharu
Published: November 2005

Antimony selenide (Sb0.4Se0.6) was found to have a very high solubility of ZnSe, and bulk crystals of ZnSe were grown from the solvent. Because of the low vapor pressure of Sb0.4Se0.6, the liquid-phase epitaxial growth of ZnSe on ZnSe substrate using an open-tube slide-boat method was successfully performed. The ZnSe layer grown on {111} B ZnSe substrate showed smooth surface morphologies. Layers thicker than 30 µm showed photoluminescence at 4.2 K characteristic of pure crystals.
Conoscopic Study of the Temporal Behavior of Electrically Driven Homogeneous L.C. Film
Authors: Yamashita Masafumi , Nozawa Shinzi , Nagai Yutaka , Hashimoto Yoshiro , Yukinari Toshiro , Ishiguro Kozo
Published: November 2005

With the same “montage method” used in a previous paper, the temporal behavior of the isogyre of a conoscopic figure of homogeneously aligned nematic liquid crystal film is studied. The isogyre appears as a straight black band soon after turning on the external field, then with ca. 4 ms time delay, it grows into a black cross. Its center is located at the final equilibrium position from the first instance of its appearance and does not shift with time. This tendency is the same as is the case of the twisted film reported in the previous paper. When the external field is turned off, the process is reversed.
Electron-Beam-Induced Charge Collection Microscopy of Undoped LEC GaAs
Authors: Tokumaru Yozo , Okada Yasumasa
Published: November 2005

Electron-beam-induced charge collection microscopy has been applied to the microscopic investigation of uniformity in undoped LEC (100) GaAs wafers. Defects such as growth striations and dislocation lines are observed in semiconducting specimens and cellular dislocation structures in semi-insulating specimens. It has been shown that this method is a useful technique for nondestructive microscopic characterization of undoped LEC GaAs wafers.
Optical Observation of Short Ultrasound Pulses in the Phase Grating Plane
Authors: Nagai Satoshi
Published: November 2005

An optical technique for the observation of the ultrasound waveform is presented. The phase grating produced by ultrasound is imaged outside an acoustic medium. The Raman-Nath parameter is extracted with a photodetector located in the image plane using an optical heterodyne method. This technique has the flat response in frequency pertinent to the short pulse measurement.
Magneto-Inertia Confinement in Dynamic Z-Pinch
Authors: Ikuta Kazunari
Published: November 2005

An approach to fusion with z-pinch plasma of density 1020 cm-3 and of length 102 cm is discussed. A method of generating a 102 cm plasma column is proposed using a version of dynamic z-pinch with the help of a new electrode configuration.
Surface Electronic Structures of Ge(111) Surfaces as Revealed by Temperature Dependent UPS
Authors: Yokotsuka Tatsuo , Kono Shozo , Suzuki Shoji , Sagawa Takasi
Published: November 2005

Angle-resolved ultraviolet photoelectron spectra have been measured for Ge(111) surfaces at temperatures from ambient T to 730°C. It is found that no essential changes in surface electronic structure occur in going from the “2×8” surface to the “1×1” surface, indicating a similarity in local surface geometries of the two. It is also found that an unoccupied surface state, as was found previously with electron energy loss spectroscopy, reveals its existence at 200°C≤T≤400°C. Angular dependence of photoelectron intensity of the unoccupied surface state is similar to that of the metallic surface state of the Si(111) 7×7 surface.
Detection of Hydrogen on Solid Surfaces by Low-Energy Recoil Ion Spectroscopy
Authors: Oura Kenjiro , Shoji Fumiya , Hanawa Teruo
Published: November 2005

Direct detection of hydrogen on the topmost surface of an hydrogenated amorphous silicon film has been made using a low-energy recoil ion spectroscopy method. Energies of positive and negative recoil ions (H+ and H-) produced by Ne+ ion bombardment (below 2 keV) have been measured by an electrostatic analyzer and they agree well with those predicted by elastic binary collision model between Ne and H.
ESR Dosimetry for Atomic Bomb Survivors Using Shell Buttons and Tooth Enamel
Authors: Ikeya Motoji , Miyajima Junko , Okajima Shunzo
Published: November 2005

Atomic bomb radiation doses to humans at Nagasaki and Hiroshima are investigated by electron spin resonance (ESR) from shell buttons and tooth enamel voluntarily supplied by survivors. A shell button gives a dose of 2.1±0.2 Gy with ESR signals at g=2.001 and g=1.997 while the signal at g=1.997 for the tooth enamel of the same person is 1.9±0.5 Gy. Other teeth show doses from about 0.5 Gy to 3 Gy. An apparent shielding converted to a concrete thickness is given using the T65D calculated in 1965. Teeth extracted during dental treatment should be preserved for cumulative radiation dosimetry.
High Resolution Electron Microscopic Studies of Amorphous SiO Film
Authors: Kaito Chihiro , Shimizu Tsukasa
Published: November 2005

High resolution electron microscopic (HREM) observations have been done for vacuum deposited SiO films. Areas 1∼2 nm in size with lattice fringes are seen in the micrographs. It is shown that the films are composed of a mixture of silicon and α-cristobalite.
Auto-Doping Phenomena for the InGaAsP Active Layer in DH Structure Grown by LPE
Authors: Sasai Yoichi , Yoshioka Yoshiaki , Hase Nobuyasu
Published: November 2005

The behavior of diffused Zn and Te impurities in the InGaAsP-InP DH laser structure grown by LPE has been investigated by means of secondary ion mass spectrometry (SIMS) and photoluminescence (PL) technique. Judging from SIMS profiles of these impurities in the InGaAsP active layer, we have found that a mutual diffusion occurs in this layer and that these impurities at the heterointerface pile up. The study of PL measurements has further shown that the diffused impurities influence the optical properties of the active layer.
Application of Hydrogenated Amorphous-Silicon to Bipolar Transistors
Authors: Nara Yasuo , Matsumura Masakiyo
Published: November 2005

Application of hydrogenated amorphous-silicon to bipolar transistors has been investigated for the first time. A novel device structure suitable for bipolar transistor operation is discussed in detail and its fabrication process and the preliminary experimental results are also described. The experimental results show that the common-emitter current gain β exceeded 2.
Space-to-Time Conversion of Optical Signal Using Fiber Delay and Its Application to Accelerator Beam Profile Monitor
Authors: Ogata Atsushi
Published: November 2005

A set of optical fibers is described where the lengths of fibers make an arithmetic series. Spatial distribution of input light is converted into time distribution at the output. Accepting the output light by a single optical detector, we can display the spatial distribution in a single trace on an oscilloscope. This is useful in studying the profile of the synchrotron radiation of an electron storage ring.
CW Lasing Characteristics of Visible InGaAsP Lasers Grown on GaAsP Substrates
Authors: Fujimoto Akira , Watanabe Hideaki , Takeuchi Masashi , Shimura Mikihiko
Published: November 2005

Continuous wave operation of visible-light emitting InGaAsP injection lasers grown on GaAs0.61P0.39 substrates by liquid phase epitaxy was obtained in the temperature range of 98–197 K. Their lasing wavelength was 630 nm at 197 K. The characteristic temperature T
0 was estimated to be 58 K.
On Ion Beam Energy Conversion into Soft X-Rays
Authors: Unterseer K. , J. Meyer-ter-Vehn J. Meyer-ter-Vehn
Published: November 2005

Ion beam energy conversion into soft X-ray is investigated by numerical simulation. The basic processes are analyzed analytically. No possibility for power amplification by pulse compression is found.
Electron Activation Energy in Si-Doped AlGaAs Grown by MBE
Authors: Watanabe Miyoko Oku , Maeda Hajime
Published: November 2005

The electron activation energy in Si-doped AlGaAs is calculated assuming the coexistence of a shallow donor center and a DX center, where the concentration of two centers was evaluated, from the previous DLTS study. The result suggests that the strange variation in donor ionization energy with the AlAs mole fraction observed in the Hall measurement is due to changes in the ratio of concentrations of the two donor centers.
Halogen Cycle Operation Test under Microgravity Conditions Using Sounding Rocket
Authors: Yamamoto Fumio , Mizutani Takayuki , Yokota Takao , Saito Masatoshi , Kanbayashi Akio , Nakahata Yoshihiro , Sawaoka Akira
Published: November 2005

Effect of halogen cycle under microgravity conditions was determined by using halogen lamp equipment on board sounding rocket TT-500 A #12 launched by the National Space Development Agency of Japan. Results show that the halogen lamp halogen cycle under microgravity conditions behaves the same as on the ground. From this result, it is foreseeable that there will be no reduction halogen cycle effect in the lamp in the image furnace on board the Space Shuttle Spacelab.
MBE Growth and Properties of AlGaAs/GaAs/AlGaAs Selectively-Doped Double-Heterojunction Structures with Very High Conductivity
Authors: Inoue Kaoru , Sakaki Hiroyuki , Yoshino Junji
Published: November 2005

The growth condition and structural parameters to achieve both extremely high mobilities, µs and high carrier concentrations, N
s were clarified for AlGaAs/GaAs/AlGaAs selectively-doped double-heterojunction structures. The growth of a relatively low substrate temperature (∼530°C) and the use of wide GaAs-well were necessary in achieving µs greater than 105 cm2/Vs. When the thickness W
sp of the undoped spacer layers was reduced, N
s was found to increase in accordance with the theory, reaching 2×1012/cm2 at W
sp=0 Å. In contrast, µs showed maximum at W
sp=90 Å, at which an extremely high conductivity exceeding 20 mS/□ at 77 K was achieved.
Phase Diagram in the System BaCO3–PbO and Crystal Growth of BaPbO3
Authors: Oka Kunihiko , Unoki Hiromi
Published: November 2005

Single crystals of BaPbO3 have been grown by the top seeded solution growth (TSSG) method. A crystallographic phase diagram for the BaCO3–PbO system has been derived by means of differential thermal analysis, quenching technique, X-ray diffraction and actual crystal growth.
Impurity Concentration Effects on Radiation Defect Introduction in InP Examined by in situ Measurement
Authors: Yamaguchi Masafumi , Yamamoto Akio , Uemura Chikao
Published: November 2005

Minority carrier diffusion length in 60Co γ-ray-irradiated InP single crystals is examined by in situ measurement using 60Co γ-ray induced current method. Anomalous behavior of defect introduction, whose rate decreases with increase in carrier concentration and saturates in high irradiation fluence, is found for room-temperature γ-irradiated InP. This defect introduction behavior is explained by considering defect generation and annihilation during irradiation. Room-temperature annealing rate of radiation-induced defects in InP is found to be proportional to carrier concentration at two-thirds power in InP.
Structural Study of PtSi/(111)Si Interface with High-Resolution Electron Microscopy
Authors: Kawarada Hiroshi , Ohdomari Iwao , Horiuchi Shigeo
Published: November 2005

The interface structure between PtSi and (111)Si has been clarified on an atomic scale for the first time, using a 1 MV high-resolution electron microscope. At the interface the transition from the PtSi lattice to the Si lattice is abrupt without the formation of any extra phase. Lattice fringe images show that the interface is heavily undulated and has atomic steps. Large lattice mismatch between PtSi and Si generates these atomic steps and extra half planes of PtSi. The observed relationship between the slope of the interface and the number of extra half planes can be explained by a simple model.
Effect of Annealing on Hydrogenated Amorphous Silicon Prepared at High Deposition Rate
Authors: Hamasaki Toshihiko , Ueda Masato , Chayahara Akiyoshi , Hirose Masataka , Osaka Yukio
Published: November 2005

Structural and electronic stabilities in hydrogenated amorphous silicon (a-Si:H) prepared at deposition rates ranging 10–50 Å/sec have systematically been investigated by observing annealing effects on the spectra of optical absorption, photoluminescence and infrared absorption. High-rate samples deposited at a substrate temperature of 200°C exhibited excellent thermal stability in electronic properties at annealing temperatures up to 465°C.
Device Layer Transfer Technique using Chemi-Mechanical Polishing
Authors: Hamaguchi Tsuneo , Endo Nobuhiro , Kimura Masakazu , Ishitani Akihiko
Published: November 2005

A device layer transfer technique, a new technique for transferring a thin device layer fabricated on the silicon wafer onto an insulating substrate, is described. The fundamental processes supporting this technique are wafer thinning using chemi-mechanical polishing and wafer fastening. A 2 µm-thick device layer with a 2 inch diameter is formed on a quartz glass substrate without significant degradation in transistor characteristics.
Preparation and Properties of Conducting Heterocyclic Polymer Films by Chemical Method
Authors: Yoshino Katsumi , Hayashi Shigenori , Sugimoto Ryu-ichi
Published: November 2005

Heterocyclic conducting polymer films are prepared by the oxidative cationic polymerization of thiophene, pyrrole and furan. Electrical and optical properties of these polymer films are similar to those using electrochemically prepared polythiophene, polypyrrole and polyfuran.
Direct Interferometric Measurement of Static and Nonlinear Wavefront Distortions of a High Power Glass Laser Beam
Authors: Toide Eiichi , Kanabe Tadashi , Arinaga Shinji , Nakatsuka Masahiro , Kato Yoshiaki , Yamanaka Chiyoe
Published: November 2005

The wavefront distortion of a large aperture (200 mm) laser beam from a high power glass laser system was directly measured using an interferometric method. The measured static and nonlinear wavefront distortions were used to calculate the intensity distributions at the far field and were then compared with the experimental data. The relationship between the wavefront distortion and the far field pattern thus established is very useful for characterizing the performance of the laser system.
Deposition of Ultra Fine Particles Using a Gas Jet
Authors: Kashu Seiichiro , Fuchita Eiji , Manabe Takeshi , Hayashi Chikara
Published: November 2005

Use of a gas jet for the transfer and deposition of metal or ceramic UFP has been studied. Individual particles having a diameter of less than 0.1 µm, are produced by the so-called gas evaporation method. Deposition of the UFP can be made by preparing a colliding gas flow with UFP on a solid surface. Uniformly distributed deposition of different metals or ceramics, regardless of specific gravity, can also be made. A similar technique is also usable with frozen gas UFP (CO2 for example). A CO2 UFP blizzard can remove photoresist without contamination or damage to a substrate (thin film chromium coated on glass). The transfer and deposit technique could be a basic method for handling UFP for industrial application.
Scaling Principle for Heterojunction Bipolar Integrated Circuit
Authors: Ohta Kuniichi
Published: November 2005

A novel scaling principle for heterojunction bipolar ICs (integrated circuits) including current and voltage scaling, a natural extension of Si device scaling, is proposed. It is shown that computer cycle time may thereby be reduced by an order of magnitude. It is theoretically verified that this scaling scheme can be realized by introducing temperature scaling and band gap scaling as well as dimensional scaling. It is assumed in this letter that the band gap scaling can be managed by present day semiconductor technology, especially for III–V compounds. These material problems will be discussed in a separate paper.
Growth of InGaAsP Quaternary by Chloride VPE
Authors: Hoshino Masataka , Komeno Junji , Ozeki Masashi
Published: November 2005

We report on the first successful growth of InGaAsP quaternary alloy by chloride vapor phase epitaxy, which uses PCl3 and AsCl3 as sources of group V elements and In and Ga as metal sources. We found that the controllability and reproducibility of the alloy composition are excellent. InGaAsP quaternary alloy with an energy gap corresponding to the light energy of 1.3 µm has been grown with lattice mismatch lower than 2×10-4.