bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Lattice Mismatch on the Solidus Compositions of GaxIn1-xP Liquid Phase Epitaxial Crystals
Authors: Ohta Jun , Ishikawa Masayuki , Ito Ryoichi , Ogasawara Nagaatsu
Published: November 2005

Liquid phase epitaxy of Ga
x
In1-x
P on (100)-oriented GaAs and GaAs0.8P0.2 substrates has been studied. Results indicate that the solidus compositions of Ga
x
In1-x
P on both substrates tend to be “locked” near the lattice matching composition. This “composition pulling” effect is shown to be consistent with a model that takes account of the contribution of lattice mismatch strain energy.
Decreased Losses in Germanium-Oxide Glass Optical Fiber Prepared by VAD Method
Authors: Takahashi Hiroshi , Sugimoto Iwane
Published: November 2005

Thick-clad germanium-oxide glass optical fiber doped with antimony has been prepared by the vapor-phase axial deposition (VAD) method. Loss values of less than 5 dB/km around 2 µm and 23 dB/km at 2.4 µm have been achieved.
Frequency-Dependent Properties of a Microbridge-Coupled Superconductor in a Magnetic Field of Two Frequency Components
Authors: Ishida Takekazu , Mazaki Hiromasa
Published: November 2005

Applying a mixing magnetic field h
1sin
2πf
1
t+h
2sin
2πf
2
t to a microbridge-coupled Tc specimen, we have measured the ac susceptibility χ1=χ'1-iχ''1 through frequency channels of f
1 and f
2. Observations show the f
2 dependence of χ''1, where f
1 is fixed. Namely, the transitions in terms of χ''1(f
1) and of χ''1(f
2) occur at different temperatures. It has been revealed that the magnetic susceptibility approaches an asymptotic form as f
2 increases.
Effect of Various Plasmas on Vacuum Deposited Amorphous and Microscrystal Silicon
Authors: Fang P. H. , Huan Zhong , Gao Yinqun , Schubert C. C. , Kinnier J. H.
Published: November 2005

A gaseous plasma of oxygen, nitrogen, hydrogen and air has been used to treat amorphous and microcrystal silicon. The resultant effect, as measured by the photovoltaic characteristics of solar cells made of these materials, is that all of these gases can be effectively incorporated into the amorphous and microcrystal silicon to produce a beneficial photovoltaic effect. There is some difference in thermal stability; nitrogen is very similar to hydrogen and is higher in stability, and oxygen and air are somewhat lower.
Determination of the Sense of Burgers Vector by Plane-Wave X-ray Topography
Authors: Ishida Kohtaro , Kobayashi Yoshinori , Katoh Hiroyuki , Takagi Satio
Published: November 2005

Dislocation images of a Si single crystal are observed by three-crystal topography with (+, +, -) setting. The images change with the diffraction condition of the topograph. The image taken out of the exact Bragg condition is sharp and its position is slightly displaced due to the strain induced around the dislocation. The sense of the Burgers vector is determined by the relation between the direction of the displacement and the diffraction condition of the topograph.
Proposal of Electro-Optical Switching and Memory Devices Utilizing Doping and Undoping Processes of Conducting Polymers
Authors: Yoshino Katsumi , Kaneto Keiichi , Inuishi Yoshio
Published: November 2005

New optical switching and memory elements utilizing the spectral change of conducting polymers by electro-chemical doping and undoping are proposed.
Very Low Dark Current P-p-P Base InGaAsP/InP Phototransistors
Authors: Kobayashi Masahiro , Sakai Shiro , Umeno Masayoshi
Published: November 2005

The characteristics of low dark current and high sensitivity InGaAsP/InP phototransistors are described. To achieve low dark current, new transistor structure which contains an N-InP emitter, P--InP/p-InGaAsP/P--InP base and N-InP collector structure is employed. In one device which has the current gain of 30 and 500 at incident power of 5 nW and 5 µW, respectively, the lowest dark current of 650 pA (3.6×10-6 A/cm2) at VCE=1 V has been obtained. The dark current of the transistor can be reduced by increasing the P--InP layer thickness at the expense of the current gain.
Improvement of a Pulse Generator for the Atom-Probe: Doubling of Pulse-Voltage
Authors: Nomura Eiichi , Horie Shiro , Nishikawa Osamu
Published: November 2005

In order to increase a pulse voltage, a stack of two mercury-wetted reed relays was employed as a switch for a voltage-pulse generator. The stacked relays doubled the attainable pulse voltage owing to an increase of breakdown voltage of the switch.
In the mass analysis of W with a high mass-resolution time-of-flight atom-probe incorporating the new pulse generator, no deterioration of mass resolution is seen over a wide range of the pulse amplitude, verifying the usefulness of the generator especially in the case where a high pulse voltage is required.
Saddle-Type Bow of As-Cut GaAs Wafers
Authors: Obokata Takeshi , Emori Haruo , Fukuda Tsuguo
Published: November 2005

Bow of as-cut GaAs wafers sliced by internal diameter diamond saw was studied. The crystals used were [001]-oriented GaAs grown by LEC technique. It was found that the bow of all wafers was a saddle type independent of doped impurities (undoped, Si-doped and Cr-doped). The form of saddle is related to particular crystal orientations of the zinc blende structure.
Formation of Cubic Boron Nitride Films by Boron Evaporation and Nitrogen Ion Beam Bombardment
Authors: Satou Mamoru , Fujimoto Fuminori
Published: November 2005

The resistivity and structure of films deposited on tantalum and rocksalt substrates by the electron beam evaporation of boron and the simultaneous bombardment of 30 keV N2
+ ion beam were studied. From observation by transmission electron microscope, it was found that cubic boron nitride was produced in the case where the prepared composition rate of boron to nitrogen was 2.5.
Binary Compound Clusters Formed by Free Jet Expansion
Authors: Saito Yahachi , Mihama Kazuhiro , Noda Tamotsu
Published: November 2005

Atom-clusters of NaCl, KCl, PbS and PbSe have been produced by adiabatic expansion of the vapor through a small nozzle. These clusters have been ionized by electron bombardment and analyzed by time-of-flight mass spectrometry. Formation of compound clusters from MX to (MX)4 has been observed for all the samples, where M represents a cation and X an anion. Alkali halide clusters are considered to keep their stoichiometry. On the other hand, for lead chalcogenides, clusters having non-stoichiometric compositions as well as those having stoichiometric compositions are formed, though the former clusters are less abundant than the latter.
A Tunable 90° Rotator Using a Total Reflection by a Monodomain Cholesteric Liquid Crystal Cell
Authors: Takezoe Hideo , Ouchi Yukio , Hara Masahiko , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

A tunable 90° rotator using a cholesteric liquid crystal cell is presented. The idea is based on a unique optical feature of cholesterics, a total reflection. In the total reflection region, linearly polarized incident light is totally reflected and the incident polarization is rotated by about 70°. In other words, 80% of the incident light intensity can be converted to the perpendicular component to the incident polarization over a relatively wide spectral range, 485 nm–670 nm. The cell of another tuning range is also easily obtained by choosing the helical pitch of cholesterics.
Direct Observation of Impact Ionization and Hot Electron Effects in GaAs
Authors: Ohyama Tyuzi
Published: November 2005

Measurements of the far-infrared cyclotron resonance of conduction electrons and the Zeeman absorption of donors in optically excited GaAs have been carried out in the presence of an electric field. The electric field dependence of the resonance intensity as well as the line shape can be explained in terms of the hot electron distribution and impact ionization of the donor electrons. Furthermore, the polaron pinning effect accounts for the nonparabolicity of the conduction band.
Organometallic Vapor Phase Epitaxial Growth of In1-xGaxAsyP1-y on GaAs
Authors: Iwamoto Takashi , Mori Kazuo , Mizuta Masashi , Kukimoto Hiroshi
Published: November 2005

In1-x
Ga
x
As
y
P1-y
(0.5≤x≤0.9, 0≤y≤0.55) layers have been grown on GaAs substrates by low-pressure organometallic vapor phase epitaxy using triethylindium (TEIn), triethylgallium (TEGa), arsine (AsH3) and phosphine (PH3). The surface morphology of the layers is mirror-like and the photoluminescence intensity is comparable to that of InGaP grown on GaAs by the same technique. The relationship between the fraction of AsH3 flow and the solid fraction of As, y, is also mentioned.
Hydrogen Incorporation Scheme in Amorphous-Microcrystalline Mixed-Phase Si: H Films
Authors: Kumeda Minoru , Yonezawa Yasuto , Nakazawa Kenji , Ueda Shoichi , Shimizu Tatsuo
Published: November 2005

Silicon-hydrogen alloy films containing both microcrystalline phase and amorphous phase (µc-Si: H) are prepared by sputtering, magnetron sputtering and glow-discharge methods. Results of NMR measurements for hydrogen in µc-Si: H are qualitatively similar to those in amorphous silicon-hydrogen alloy films except that hydrogens are easy to move and exhibit the motional narrowing effect. There seems to be little possibility of presence of a large amount of non-bonded hydrogens such as hydrogen molecules or atomic hydrogens.
LEED/AES Studies of the Ge on Si(111)7×7 Surface
Authors: Shoji Katsuyuki , Hyodo Masahito , Ueba Hiromu , Tatsuyama Chiei
Published: November 2005

Germanium was evaporated on the clean Si(111)7×7 surface at room temperature. With increase in Ge coverage θ, the intensity of the Si(LVV) AES signal decreased in accordance with a 2-dimensional growth mode up to a few monolayers, and the LEED pattern gradually changed from the (7×7) structure to a diffused (1×1) one at θ<2 monolayers and to an nonstructural one at θ>2. The LEED pattern and the AES intensity drastically changed by annealing. The Si(111)7×7 surface covered by 2 monolayers of Ge shows a (5×5) structure by annealing at temperature between 380 and 720°C.
Structural and Electronic Characterization of Discharge-Produced Boron Nitride
Authors: Miyamoto Hironobu , Hirose Masataka , Osaka Yukio
Published: November 2005

Insulating BN thin-films were prepared at a temperature below 300°C by the rf glow discharge decomposition of a B2H6+NH3+H2 gas mixture. The structure of the deposited films was amorphous and the optical bandgap was determined to be ∼5.0 eV. Utilizing the plasma-deposited BN films, Al/BN/Si MIS structures were fabricated to test the dielectric properties. The static dielectric constant of stoichiometric BN is found to be 6.5, and the breakdown-field strength exceeds 3×106 V/cm.
A Blazed Si Grating for Soft X-Ray Fabricated by Two-Stage Reactive Ion-Beam Etching
Authors: Aritome Hiroaki , Yamato Toshiya , Matsui Shinji , Namba Susumu
Published: November 2005

A blazed Si grating with a blaze angle of 3° is successfully fabricated using holographic exposure and reactive ion-beam etching. A new two-stage etching technique is developed for a grating with a blaze angle of less than 1° in Si single crystal, combining inclined and normal incident reactive ion-beam etching techniques. These diffraction gratings can be expected to be very useful in a soft X-ray region.
Quantum Mechanical Size Effect Modulation Light Sources– A New Field Effect Semiconductor Laser or Light Emitting Device
Authors: Yamanishi Masamichi , Suemune Ikuo
Published: November 2005

A new field effect semiconductor laser or light emitting device is proposed and analysed, in which the photon emission rate is modulated by the gate voltage mainly through changes in spatial distributions of the carriers. The switching speed in the device is expected to be free from recombination lifetime limitation in specific operation modes.
The Effect of Temperature on Hot Electron Trapping in MOSFET's
Authors: Satoh Yoshihiro , Miyamoto Kazutoshi , Matsumoto Heihachi
Published: November 2005

The temperature dependence of the threshold voltage shift has been studied for long term device degradations. The threshold voltage shift strongly depends on temperature and this is mainly caused by the temperature dependence of the effective trap density. The model assuming that the traps with an emission probability higher than 10-5∼10-6 are useless as electron traps agrees well with the experimental results.
Au–Si–Be Liquid Metal Ion Source for Maskless Ion Implantation
Authors: Hashimoto Eizo Miyauchi Hisao , Utsumi Takao
Published: November 2005

A new alloyed-liquid-metal ion source for ion implantation into III-V compound semiconductors has been developed. A ternary alloy consisting of Au, Si & Be is used as the liquid metal for this ion source which is capable of emitting p-type dopant (Be), n-type dopant (Si), and Au ions from a single emitter tip. Threshold voltage for emitting ion current is about 6 kV and Be++, Si++ and Au+ ions are dominant. Energy spreads of Be and Si ion beams are less than 10 eV, while that of Au was greater than 15 eV.
Secondary Electron Emission from Aluminum by Argon and Oxygen Ion Bombardment below 3 keV
Authors: Yamauchi Yasushi , Shimizu Ryuichi
Published: November 2005

The potential emission from aluminum under argon ion bombardment and an enhanced emission under oxygen ion bombardment have been investigated for an aluminum sample. For this a compact energy analyzer was made to measure energy distribution of secondary electrons at certain detection angle as well as total yield for the energy range from 0.7 to 3.0 keV. The results show that the electron yield owing to potential emission is between about 0.07 and 0.08 for argon ions and the enhancement in kinetic emission by oxygen ion bombardment results in marked increase in the yield of more than one order of magnitude higher than that for argon ions.
Electric Field Dependence of Variance in Helicoidal Pitch Distribution and of Light Transmittance in the Ferroelectric Liquid Crystal DOBAMBC
Authors: Kai Shoichi , Narushige Yasushi , Nishida Koji , Imasaki Masahide
Published: November 2005

In S*
C phase of DOBAMBC, electric field dependence of variance of the helicoidal pitch and of light transmittance was studied using a photodensity analyzer consisting of a video camera and a personal computer. When a temperature deviation from the transition point Tc between SA and S*
C is large, the minimum transmittance is observed at the field of the maximum variance of the pitch with both increasing and decreasing field. This shows that an increase in the variance induces an increase in light scattering. The increase in variance is qualitatively explained as the result of imhomogeneous realignment of pitch by applying the field to finite size domains.
Transparent and Highly Conductive Films of ZnO Prepared by RF Sputtering
Authors: Ito Kentaro , Nakazawa Tatsuo
Published: November 2005

Zinc oxide thin films with the resistivity of 5×10-3Ω·cm and the transparency of above 80% at the wavelength between 400 and 800 nm have been prepared by conventional rf sputtering in pure argon from a zinc oxide target. A close relation of their electrical characteristics with crystallographic characteristics is found using X-ray diffraction analysis. The low resistivity films consist of very small crystal grains, the c-axis of which is not preferentially oriented or is weakly oriented parallel to the substrate surface.
X-Ray Topographic Study on Rochelle Salt Crystal
Authors: Ishida Kohtaro , Umezawa Kikuo , Kawata Masanobu , Takagi Satio
Published: November 2005

Plane wave topographs of Rochelle salt crystal are taken at various temperatures for 440 reflection with MoKα1 radiation. The strong diffraction contrast due to the phase transition is observed. In the ferroelectric phase, double peaks are observed on the rocking curve. The separation of the peaks changes with temperature and a model for the possible explanation of its cause is proposed. A fine maze-like structure, which changes with temperature, is also observed in the ferroelectric phase.
New Negative Conductances in GaAs n+-n-n+ Ballistic Diodes
Authors: Aishima Asuo , Fukushima Yoshifumi
Published: November 2005

Two terminal conductances for GaAs n+-n-n+ ballistic diodes are calculated by using a simplified diode model. It is found from the results that, due to space charge transit time effects, negative conductances appear in such ballistic diodes at a far infrared frequency range. It is also demonstrated that diode conductance-frequency characteristics are affected significantly by the plasma oscillation frequency.
Enhancement of a Thin Film Indium Antimonide on Lithium Niobate Convolver Output by Transverse Biasing
Authors: Onishi Shinzo , Eschwei Mary , EL-Asir Bassam , Wang Wen-Chung
Published: November 2005

A new means of enhancing convolver output has been found. Application of a transverse drift field to an indium antimonide (InSb) film enhances the convolver output, which was taken in the width direction transverse to both the sonic propagation and the substrate normal. This convolver and two surface acoustic wave amplifiers (SAW AMP), made by deposition of InSb films on Y-cut, Z-propagation lithium niobate (LiNbO3), are integrated and operated at a center frequency of 150 MHz. Preliminary work has resulted in an input-output efficiency of less than -7 dB with this device.
A Long-Lasting Polyacetylene Battery with High Energy Density
Authors: Nagatomo Takao , Honma Tetsuya , Yamamoto Chiaki , Negishi Kuniaki , Omoto Osamu
Published: November 2005

An n-(CH)/LiClO4/p-(CH) battery (1.0 M LiClO4 in propylene carbonate) prepared by passing 2.14 C (dopant concentration y=0.072) exhibited an open-circuit voltage of 3.5 V and an initial short-circuit current of 28 mA ((CH)x electrode; ∼4 mg). Experimental energy density of 424 W-hr/Kg (at a stored charge of 10.8 C (y=0.364), a liberated charge of 4.52 C and a mean voltage of 2.7 V) was obtained based on the weight of the (CH)
x
film (both electrodes; ∼8 mg). No degradation of the polyacetylene battery was observed even after 2000 successive charge/discharge cycles, each cycle consisting of a 10 min discharge at a constant resistance of 50 kΩ and a 10 min charge at 0.1 mA (a stored charge of 0.06 C (y=0.002)).
Radiation Annealing of Si- and S-Implanted GaAs
Authors: Ito Kazuhiko , Yoshida Masahiro , Otsubo Mutsuyuki , Murotani Toshio
Published: November 2005

Radiation annealing of Si- and S-implanted GaAs using tungsten lamps was studied. In capless radiation annealing, electrical activations were 70–80%, which were 20–30% higher than that in conventional furnace annealing for a low dose below 2×1013 cm-2. Effects of encapsulation on electrical activation were also investigated. It was found that electrical activations of high dose samples were improved by encapsulating the surface with SiO2 film for Si-implanted samples and with Si3N4 film for S-implanted samples.
Eu2+ as an Optical Probe to Analyse the Influence of Sr-Second Phase Precipitates on the Hardening Behavior of NaCl
Authors: H. E. Carrillo , Solé J. García , Soullard J. , J. Rubio O. J. Rubio O.
Published: November 2005

The effect of the state of precipitation of strontium ions on the hardneing behavior of NaCl has been investigated. The data reported in this paper demostrate that, depending on temperature, the Sr-precipitation processes affect in different ways the yield stress of supersaturated solid solution crystals. In order to get a better insight into the obstacles responsible for the changes in the value of the yield stress, the europium ion was emplyed as an optical probe taking advantage of the fact that this ion can be incorporated into the different Sr-second phase precipitates modyfing its optical spectra due to changes in the local crystalline environment.
A New Method for Measuring the X-Ray “Pendellösung” Beats at the Center of the Borrmann Fan Using White Radiations
Authors: Takama Toshihiko , Noto Nobuhiko , Kobayashi Kazuyoshi , Sato Shin'ichi
Published: November 2005

A new technique is proposed to measure the X-ray Pendellösung intensity beats using white radiations and parallel-sided single crystals. The beats are measured at the center of the Borrmann fan on the exit surface of a thick Si specimen. The atomic scattering factors of Si are determined for the 220 reflection with an accuracy remarkably higher than that in the previous method.
Effect of Substrate Materials on Recording Sensitivity in Optical Storage Media
Authors: Fujimori Susumu , Yamazaki Hiroki , Asano Yoshihiro
Published: November 2005

The effect of substrate materials on the recording sensitivity in optical storage media was investigated. Evaporated Te films on various kinds of substrates were used as optical storage media. The recording sensitivity in Te films varied with the substrate materials. The temperature rise during exposure of laser beam was calculated on the basis of a thermal diffusion model. The temperature at threshold pulse duration was found to vary with the substrate materials. Therefore, the recording sensitivity is considered to depend not only on the thermal diffusion, but also on other factors such as a surface condition of substrate.
Electrical Resistivity of Undoped GaAs Single Crystals Grown by Magnetic Field Applied LEC Technique
Authors: Terashima Kazutaka , Katsumata Tooru , Orito Fumio , Kikuta Toshio , Fukuda Tsuguo
Published: November 2005

We have grown undoped GaAs single crystals by magnetic field applied LEC (MLEC) technique and measured their electrical and optical properties. The most striking result was that the electrical resistivity of undoped GaAs changed from being semi-insulating (108 ohm-cm) to semi-conducting (10 ohm-cm) by increasing the magnetic field (0 to 1300 Oe). PL, DLTS and SIMS measurements suggest that the decrease of resistivity is mainly due to the decrease in concentration of the deep level defects.
Contact Resistance of Al/Si Ohmic Electrodes Formed by Rapid Lamp Sintering.
Authors: Hara Tohru , Suzuki Hidenori , Furukawa Masakazu , Amemiya Kimio
Published: November 2005

Reduction of contact resistance was achieved in Al/Si ohmic electrodes sintered by halogen lamp rapid heating. Contact resistance measurements were made for the electrodes formed on highly doped shallow p-Si layers, where lamp sintering was performed at 450°C. The contact resistance was low and uniform within a wafer when compared with that for conventional furnace sintering. A specific contact resistance of 4.0×10-6 Ohm-cm2 was achieved for p
+ layers. The Al spikes and Si precipitates could be markedly reduced in this short time sintering.
Anisotropic Excluded Volume Effect and Alignment of Nematic Liquid Crystal in a Sandwich Cell
Authors: Okano Koji
Published: November 2005

It is shown that the orientation dependent excluded volume interaction between elongated nematic molecules and the cell walls always favors the planar alignment of nematic liquid crystals. For thermotropic liquid crystals the anchoring energy of this effect amounts to several erg/cm2.
Characterization of Deep Levels in Semi-Insulating GaAs Crystals by a Spectroscopic Photoelectrochemical Current
Authors: Otsubo Mutsuyuki , Murotani Toshio
Published: November 2005

A new method for detecting deep levels in semi-insulating GaAs crystals is proposed. With this method determination of deep level distributions over a wafer by a spectroscopic photoelectrochemical current is possible. The deep levels of 1.13 eV, 1.02 eV, 0.98 eV, and 0.70 eV have been detected in both undoped and Cr-doped materials. Two additional deep levels of 0.78 eV and 0.65 eV were detected in Cr-doped materials. A peak intensity ratio of the 1.13 eV band to the 1.43 eV increased linearly with increasing chromium content in the crystals. Nonuniform distribution of deep levels in LEC GaAs crystals has been found.
Comparison of Triple Point Temperatures Realized in Two Different Types of Sealed Cells
Authors: Tamura Osamu , Sakurai Hirohisa
Published: November 2005

The temperature differences between the triple points of neon, oxygen and argon realized in two types of sealed cells designed by the Istituto di Metrologia “G. Colonnetti” (IMGC, Italy) and the National Research Laboratory of Metrology (NRLM, Japan) are measured. The triple point temperatures for neon and argon agree within the error of measurement between the two types of cells, while the oxygen triple point of the NRLM cell is 1.4 mK higher than that of the IMGC cell.
Confirmation of Tunneling Current via Traps by DLTS Measurements in InGaAs Photodiodes
Authors: Trommer R. , Albrecht H.
Published: November 2005

A detailed analysis of the reverse characteristics of In0.53Ga0.47As pin-photodiodes at various temperatures reveals, besides generation, diffusion and band-to-band tunneling of carriers, an additional contribution to the dark current due to tunneling through an energy barrier of 0.16±0.02 eV. In deep-level transient spectroscopy measurements a thermal activation energy of 0.57±0.01 eV, equal to the gap energy minus the tunneling barrier, has been found. From these two measurements it can be concluded that thermal activation of deep traps and subsequent tunneling of carriers into band states leads to the additional dark current component.
Direct Observation of Lattice Arrangement in MBE Grown GaAs–AlGaAs Superlattices
Authors: Okamoto Hiroshi , Seki Masahiro , Horikoshi Yoshiji
Published: November 2005

Observation is made of a cross section including the growth direction of an MBE grown GaAs–Al0.28Ga0.72As superlattice structure by a transmission electron microscope with a resolution of 1.4 Å. Relevant atoms are observed to be regularly aligned even across the heterointerface. There is no alloy clustering observed in the ternary alloy layer. Dislocation is clearly observed as a local disorder in lattice alignment for the first time in the MBE grown layer.
Surface Plasmon Dispersions of Ag Adsorbed Si(111) Surfaces Studied by Angle-Resolved Electron Energy Loss Spectroscopy
Authors: Horioka Keiji , Iwasaki Hiroshi , Maruno Shigemitsu , Li Sung Te , Nakamura Shogo
Published: November 2005

Surface plasmon dispersions (SPD) on clean Si(111)7×7 and three Ag adsorbed surfaces, RT deposited, √3-, and 3×1-structured surfaces were measured. The SPD on the clean surface was negative and similar to that of Si(001)2×1, but those of Ag deposited surfaces were positive. Hydrodynamic calculations of the SPD using the two step charge density model of the surface explained well the experimental SPDs on the Ag adsorbed surfaces and gave the charge distributions on the surfaces. For the clean surface the two step model was not adequate.
Enhancement of Electrical Conductivity of Polyacetylene by Electron Beam Irradiation in the Presence of Dopant
Authors: Yoshino Katsumi , Hayashi Shigenori , Ishii Gaku , Inuishi Yoshio
Published: November 2005

Electrical conductivity of (CH)
x
doped with various dopants like SF6, C2H2, etc. which are usually not effective in increasing conductivity, is found to be enhanced by irradiation with the electron beam. These facts are tentatively ascribed either to the radiation induced complex formation, to the formation of cross-linking preserving the conjugated double bond scheme, or to the effective doping by the molecular fragments created by the decomposition of dopants by the electron beam irradiation.
Preheating Energy in a Soft-X-Ray-Accelerated Foil
Authors: Shiraga Hiroyuki , Sakabe Shuji , Okada Kazuyuki , Mochizuki Takayasu , Yamanaka Chiyoe
Published: November 2005

Preheated temperature in a soft X-ray driven ablation was found by a double foil experiment to be Tph=2∼12 eV for a 1.7 µm thick Al target at the incident X-ray irradiance of I
x=1013 W/cm2. This preheating was caused by the higher hν component (∼1 keV) of the soft X-ray spectrum. Its energy flux was also estimated to be 27∼260 J/cm2.
Low-Energy Electron Energy-loss Spectra Associated with Reconstructed Structure on Si(111) Surface
Authors: Shigeta Yukichi , Maki Kunisuke
Published: November 2005

Low-energy electron energy-loss spectra from the Si(111) surface were obtained under a surface wave resonance condition under which the wave vector of diffracted electrons is parallel to a row of the 1/7-order superlattice rods in 7×7 structure: A peak related to surface dangling bond at 1.5 eV in the energy-loss value Δ
E, and a peak due to the excitation of surface plasmon at Δ
E=8.5 eV are enhanced at each height. Surface plasmon peak shifts to 10.5 eV when the condition is not satisfied. When the surface changes from a 7×7 structure to a 1×1, the decrease in these peak heights is also observed.
Mass- and Electron-Spectroscopic Observation of Resist Decomposition by Synchrotron Radiation
Authors: Ichimura Shingo , Hirata Masahiro , Tanino Hiroshi , Atoda Nobufumi , Hoh Koichiro , Ono Masatoshi
Published: November 2005

Analytical techniques of mass- and electron-spectroscopy were applied to the observation of lithography by synchrotron radiation (SR). During the exposure of positive resist to SR, the tendency of side-chain components easily dissociating was shown by mass spectroscopy. In-situ analysis with electron spectroscopy showed that the height of a peak appearing at low energy increased during the exposure when the power density of SR was high. This increase was closely related to the reduction in the film thickness by SR due to the dissociation of constituent molecules of the resist.
VPE-Grown 1.3 µm InGaAsP/InP Double-Channel Planar Buried-Heterostructure Laser Diode with LPE-Burying Layers
Authors: Yanase Tomoo , Kato Yoshitake , Mito Ikuo , Kobayashi Kenichi , Nishimoto Hiroyuki , Usui Akira , Kobayashi Kohroh
Published: November 2005

Hydride-VPE grown 1.3 µm InGaAsP/InP double-channel planar buried-heterostructure laser diodes with LPE burying layers were fabricated. 19.5 mA CW threshold current, 47% external differential quantum efficiency, both at 25°C, 50 mW CW operation, high-temperature CW operation up to 120°C and threshold characteristic temperature T0 as high as 72 K, have been obtained.
Electrical Discharge Channel in Sodium Vapor Initiated by Resonant Laser Light
Authors: Tamura Hideki , Mogi Jun-ichi , Horioka Kazuhiko , Kasuya Koichi
Published: November 2005

A z-discharge channel in sodium vapor was initiated by a laser beam, which was tuned to the sodium D resonance line (λ=589 nm). Applying a voltage sufficiently lower than the self-breakdown voltage, the discharge of ∼40 cm in length was initiated by laser radiation of modest power density. Streak-camera photographs showed that the laser-initiated discharge channel was produced just along the laser beam path. It was confirmed that the resonant laser light was very effective for the channel initiation.
Bound-Exciton Luminescence of Cu-Doped ZnSe
Authors: Huang Shi-Min , Nozue Yasuo , Igaki Kenzo
Published: November 2005

As an experimental approach to clarify the correlation between doped impurity and native defects, copper was deped at a low temperature to high-purity ZnSe crystals with controlled deviation from stoichiometry by a previous heat treatment under molten Zn or saturation pressure of Se. Photoluminescence was measured and examined as a function of deviation from stoichiometry. The site selection doping of Cu was achieved by controlling native defect concentrations. I1
deep lines are known to arise from acceptors of two different origins, VZn and CuZn.
Lateral Spreads of Be and Si in GaAs Implanted with a Maskless Ion Implantation System
Authors: Miyauchi Eizo , Arimoto Hiroshi , Bamba Yasuo , Takamori Akira , Hashimoto Hisao , Utsumi Takao
Published: November 2005

Submicron Si and Be ion beams have been implanted into GaAs using a 100 kV maskless ion implantation system with a liquid metal ion source which is capable of emitting double ion species (Si++ and Be++). Both ion beams are implanted at 160 keV with the dose of 1012 to 1015 cm-2. The profiles of the implanted dopants have been estimated by observing the stain etching patterns on the cleaved planes before and after annealing. It has been found that high dose implantation results in a considerable lateral impurity spread of 1 µm or more, even with the focused ion beams having a diameter of 0.1 µm. However, doping of submicron width can be realized with relatively low doses or with shallow implantation.
Epitaxial Si Layer of Si-BP-Si Structure
Authors: Sugiura Souichi , Yoshida Tohru , Shono Katsufusa
Published: November 2005

Boron monophosphide (BP) was epitaxially grown on an Si substrate and Si was also grown on the BP. On the Si epitaxial layer, PMOS transistors and inverter and flip-flop circuits were fabricated. The CV curve measured at 1 MHz gave a donor concentration near the surface of 2×1016 cm-3. The PMOS transistors gave a threshold voltage of -2.6±0.6 V and a surface hole mobility of 230±30 cm2/V.s. for SiO2 at a thickness of 0.1 µm.
Optically Pumped Laser Operation of InGaAsP/InGaP Double Heterostructures Grown by Metalorganic Chemical Vapor Deposition
Authors: Iwamoto Takashi , Mori Kazuo , Mizuta Masashi , Kunimoto Hiroshi
Published: November 2005

InGaAsP/InGaP double heterostructures have been grown on GaAs(100) substrates by low pressure metalorganic chemical vapor deposition. We have carried out a lasing experiment with a cleaved sample of ∼200 µm width by optical pumping. At high excitation levels, we have observed a stimulated emission of a wavelength of 717 nm at 150 k. The threshold power density is estimated to be about 4.5×104 W/cm2 at this temperature. We also mention the room-temperature lasing operation of similar double heterostructure samples.
A Direct Coupled Josephson Sampler
Authors: Akoh Hiroshi , Sakai Shigeki , Yagi Akihiko , Hayakawa Hisao
Published: November 2005

A direct coupled Josephson sampler with a single junction as a sampling gate which is directly connected with a sampler pulser and unknown signal sources by resistors is reported. Devices are fabricated by a Pb-alloy technology with a minimum size of 2.5×2.5 µm2 and a current density of 4 kA/cm2 for junctions. The sampler reconstructs a latching waveform with a 10 ps rise time from an interferometer within a few µA current sensitivity.
Characterization of SOS Films Grown with Amorphous Si Buffer Layers by MOS FET's
Authors: Ishida Makoto , Yasuda Yukio , Wakamatsu Hidetoshi , Abe Hiroshi , Nishinaga Tatau , Nakamura Tetsuro
Published: November 2005

Electrical properties of Si films grown epitaxially on sapphire substrates with amorphous Si buffer layers (less than 40 Å) have been studied by fabricating n-channel MOS FET's. The effective mobility of the MOS FET's fabricated on SOS with the buffer layer was 1.36 to 1.5 times as large as the one without the buffer layer, at V
G-V
T=4V. The SOS film was grown at a slow growth rate (550 Å/min) and thickness was 0.55 µm. This result indicates that the present growth method is useful for thinning Si films as VLSI devices.
Actively Mode-Locked and Q-Switched YAG Laser with Precise Synchronizability
Authors: Tomie Toshihisa , Kasai Takeshi , Yano Masaaki
Published: November 2005

A system is described which generates synchronizable laser pulses with low temporal jitter (\lesssim30 ps). The conventional LC discharge pumping scheme is used. The laser is actively mode-locked by an A-O modulator and Q-switched by a Pockets cell. Pulses of various widths (200 ps∼1 ns) can be obtained with the use of intra-cavity etalons and variation of the rf power to the A-O modulator. The stability of the pulse energy is very high (∼3%).
GaAs Light Emitting Diodes Fabricated on SiO2/Si Wafers
Authors: Shinoda Yukinobu , Nishioka Takashi , Ohmachi Yoshiro
Published: November 2005

GaAs LEDs have been successfully realized on thermally oxidized Si wafers. Ge layers were recrystallized on tungsten coated SiO2/Si wafers and used as substrates for GaAs epitaxial growth. Light emission of around 9000 Å was observed at room temperature.
Characteristics of Low Frequency Cryogenic Antennas for Gravitational Radiation
Authors: Owa Soichi , Tsubono Kimio , Hirakawa Hiromasa
Published: November 2005

Characteristics of low frequency mechanical antennas for gravitational radiation are presented. The problems arising from the very long relaxation time and the transducer noise are discussed.
Silicon Thin-Film Formation by Direct Photochemical Decomposition of Disilane
Authors: Mishima Yasuyoshi , Hirose Masataka , Osaka Yukio , Nagamine Kunihiro , Ashida Yoshinori , Kitagawa Nobuhisa , Isogaya Kazuyoshi
Published: November 2005

Silicon thin-films have been deposited by the direct photolysis of disilane at a substrate temperature below 300°C. The growth rate depends on irradiation intensity of a low pressure mercury-lamp, and a typical rate of 15 Å/min has been obtained under ∼0.08 watts/cm2 illumination, regardless of substrate temperature. The deposited films are composed of an amorphous network containing bonded-hydrogen in the range 6–9 at.%. The bonding configurations of SiH groups varied from silicon dihydride to monohydride with increasing substrate temperature, and correspondingly the dark conductivity decreased from 10-7 to 10-11 Ω-1cm-1. A broad photoluminescence peak at 1.4 eV was observed for a specimen grown at 200°C.
Temperature Dependence of the Sodium Concentration over the Sodium Tungsten Bronze (Na0.79WO3) Surface Studied by LEED
Authors: Nakamatsu Hirohide , Yamamoto Yukihiro , Kawai Shichio , Oura Kenjiro , Hanawa Teruo
Published: November 2005

Temperature dependence of the LEED intensity of a tungsten bronze Na0.79WO3(001) surface shows that the sodium concentration in the subsurface region increased as the temperature rises, while that at the topmost surface was kept constant in the (2×1) ordered phase.
Selective Meltbacked Substrate Inner-Stripe AlGaAs/GaAs Lasers Operated under Room Temperature CW Condition
Authors: Kishino Katsumi , Kinoshita Susumu , Konno Satoshi , Tako Toshiharu
Published: November 2005

A novel lateral-mode controlled AlGaAs/GaAs inner-stripe laser is demonstrated which is fabricated by a one-step liquid phase epitaxial process using a newly developed selective meltback technique. The laser consists of V-groove substrate and six Al
x
Ga1-x
As layers with different Al content forming a built-in rib-waveguide structure. In the fabrication, difference of meltback speed between GaAs and Al0.5Ga0.5As crystals was utilized. It was found that GaAs crystal was meltbacked rapidly by a factor of about fifteen compared with Al0.5Ga0.5As layer. The laser fabricated was operated under CW condition at 20°C with threshold current of 65 mA.
Deep-Level Luminescence in Ni-Diffused GaAs
Authors: Fujiwara Yasufumi , Kojima Atsushi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

The deep-level photoluminescence associated with Ni deep acceptor has been investigated in various kinds of Ni-diffused GaAs. It has been found that the luminescence related to Ni deep acceptor drastically changes from the surface to the deep region of Ni-diffused GaAs. In particular, the luminescence previously attributed to Ni–S pairs is strongly observed near the surface of all the GaAs samples doped with a variety of donor impurities. The in-depth profile measurements on these Ni-related luminescence intensities have revealed the builtup of S atoms in the vicinity of the surface region of Ni-diffused GaAs, which is probably due to the redistribution of the background S donors in GaAs bulk crystals during the high-temperature diffusion of Ni into GaAs.
Characteristics of Intense Ion Beam in Pinch Reflex Diode
Authors: Yoshinouchi Atsushi , Ozaki Tetsu , Miyamoto Shuji , Imasaki Kazuo , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

Dependence of intense ion beam divergence on local electron density in diode, difference of the divergence between protons and carbon ions and time varying self-focusing effect were investigated. Experiments were preformed on a Reiden IV generator, loading pinched e-beam ion diode or pinch reflex ion diode. The higher electron current density caused larger beam divergence. According to measured number ratios of carbon to proton, the carbon ions might have smaller divergence than protons. Heavier ions as carbon ions might be suitable for a tighter focus.
Anomalous Behavior of Helicoidal Pitch in Surface Induced Transition from Winding of Unwinding Chiral Smectic C
Authors: Kai Shoichi , Nakagawa Masahiko , Narushige Yasushi , Imasaki Masahide
Published: November 2005

We have studied the thickness dependence of helicoidal pitch in order to understand the mechanism of the structural change from winding to unwinding chiral smectic C phase. The pitch and critical thickness were measured for various temperatures using wedge type cells with the wedge angle varied from 0.06 to 0.21°C. Thickness and temperature dependence of the pitch have divergent tendencies toward certain respective thicknesses and temperatures. It is considered that the unwinding phase in the thin cell is not smectic A but chiral smectic C. A surface induced reentrant-like phenomenon similar to that field induced is observed.
Direct Observation of the Movement of Vertical Bloch Lines in Ho–Co Sputter-Deposited Films
Authors: Suzuki Takao
Published: November 2005

The presence of two types of a vertical Bloch line pair in a sputter-deposited Ho–Co alloy thin film with a perpendicular magnetic anisotropy are directly observed by high voltage electron microscopy. One type is that in which two Bloch lines of a pair move in the same direction in the wall responding to a magnetic field applied normal to the film plane, the “winding” type. The other is called the “unwinding” type where two Bloch lines move in a direction opposite to each other.
Growth of Hydrogenated Germanium Microcrystal by Reactive Sputtering
Authors: Imura Takeshi , Tashiro Mamoru , Ohbiki Tohru , Terauchi Hitoshi , Hiraki Akio , Tsuji Kazuhiko , Minomura Shigeru
Published: November 2005

Microcrystalline germanium (µc-Ge) was prepared by reactive sputtering in H2 of pressure about 1 Pa and 270 Pa at a substrate holder temperature 150°C. The average diameter of microcrystals, about 40 nm, was larger than that of microcrystalline silicon (µc-Si) obtained by the same technique. Hydrogen of 1–3 at.% was detected in the µc-Ge film by the infrared absorption spectrum. Hydrogen environment in µc-Ge was discussed in comparison with µc-Si.
Two-Dimensional Analysis of Thermal Oxidation of Silicon
Authors: Sakina Yasuharu , Ohno Tsuneo , Matsumoto Satoru
Published: November 2005

Step-shaped (110) oriented silicon wafers are oxidized in dry O2 (900–1150°C) and the cross sectional views of oxide are observed by scanning electron microscopy. At lower temperature (900–950°C), the oxide thickness at te edge the reduced compared to the other regions, but the reduction cannot be observed at higher temperatures (1000–1150°C).
Vapor and Solid Phase Epitaxies of ZnSe Films on (100)GaAs Using Metallic Zn and Se
Authors: Muranoi Tetsuo , Furukoshi Mitsuo
Published: November 2005

Low temperature growth of ZnSe layers on (100)GaAs substrates has been performed from the vapor phase using metallic Zn and metallic Se as source materials. Before deposition, the substrate was thermally etched in an H2 flow at 500 or 550°C for 5 min. Epitaxial growth was successful above 230°C. An activation energy of 10 kcal/mol was obtained for the deposition process. Films grown at 400°C showed low resistivity (on the order of 1 Ω·cm) when the flow rates of Zn and Se were almost the same. Solid phase epitaxy (SPE) occurred at 400°C for the micro-crystalline films deposited at 180–220°C on a thermally etched substrate.
Characteristics of Concave Curved Crystals for X-Ray Diagnostics of High-Temperature Plasma
Authors: Morita Shigeru , Kadota Kiyoshi , Fujita Junji
Published: November 2005

The characteristics of four crystals (LiF(200), Ge(220), LiF(220) and Quartz(2023)) for a Johann type crystal spectrometer with Photo Diode Array have been investigated from observations of FeKα1,2 characteristic X-ray. The results are tabulated with their resolution power and relative sensitivities. They were applied also to the X-ray spectroscopic measurements of a high-temperature plasma. The fine structure of the iron oxygen-like Kα lines has been resolved by the Quartz(2023) crystal.
Improvement of Ductility of Melt Spun Cu–Al–Ni Shape Memory Alloy Ribbons by Addition of Ti or Zr
Authors: Matsuoka Saiji , Hasebe Masami , Oshima Ryuichiro , Fujita Francisco Eiichi
Published: November 2005

In order to refine the grain sizes of Cu–Al–Ni shape memory alloys and improve the brittleness caused by intergranular fracture during deformation, the melt spun technique was applied to obtain alloy ribbons with a mean grain size of about 1 µm. However, the β1 phase of the alloy ribbons with fine grain structure was still brittle. The brittleness of the material was remarkably improved without loss of the good shape memory effect by adding a small amount of Ti or Zr, which has a strong affinity for oxygen.
Gap State Spectroscopy in Amorphous Selenium Photoreceptors
Authors: Naito Hiroyoshi , Motomura Kohta , Okuda Masahiro , Nakau Tanehiro , Matsushita Tatsuhiko
Published: November 2005

We propose a method useful for studying the energy distribution of deep gap states in amorphous semiconductors. The method is a sensitive and direct technique based upon the analysis of time dependence of residual voltage in photoreceptors under isothermal conditions. This enables us to map out the energy distribution of deep gap states in amorphous semiconductors. Experimental results using the method for amorphous selenium photoreceptors are demonstrated. Our results are in good agreement with those in the literature.
Correlation between Dislocation Distribution and FET Performances Observed in Low Cr Doped LEC GaAs
Authors: Nanishi Yasushi , Ishida Satoru , Miyazawa Shintaro
Published: November 2005

Definitive correlation between dislocation distribution and distribution of FET performances in low Cr (0.155∼0.180 wt ppm) doped LEC GaAs was obtained by simultaneous characterization of (100) and (010) wafers. Drain-source currents (I
ds) in the high EPD area were higher than those in the low EPD area. Micro-scale correlation between lineage-like dislocations and I
ds distribution was also clearly observed. Implications of these results on the size of a dislocation-influenced area are discussed.
Study of 0.8 eV Deep Level Photoluminescence in Undoped LEC Semi-Insulating GaAs
Authors: Kikuta Toshio , Terashima Kazutaka , Ishida Koichi
Published: November 2005

Detailed photoluminescence investigation was made on undoped LEC semi-insulating (SI) GaAs crystals in which a 0.8 eV deep emission band was dominantly observed. In crystals grown from the melt of different composition, intensity of the 0.8 eV band increased with increasing As fraction in the melt. Furthermore, in slightly Ga-rich crystals, it rapidly decreased at the tail of the boule with transition to a heavily Ga-rich condition. These results suggest that the 0.8 eV band is associated with a native point defect such as AsGa antisite defect. In addition, more sensitive melt composition dependence of resistivity was observed in the 0.8 eV dominant crystals compared with those reported by Holmes et al. and by Ta et al.
Improvement of Depth Resolution in Sputter Profiling by Cooling Specimens
Authors: Ishikawa Kazuo , Hamasaki Sei-ichi , Goto Keisuke
Published: November 2005

A substantial improvement in the depth resolution of sputter-depth profiles obtained using Auger electron spectroscopy was attained by cooling specimens to nearly liquid-nitrogen temperature during the sputtering process. The effectiveness of this method is illustrated by comparing profiles obtained at different temperatures from the simultaneously prepared Ag/Cu multilayer thin film structures. It is presumed that the effects of the cooling are caused by the suppression of irradiation-induced diffusion and/or of annealing of the more or less amorphized surfaces.
Efficient Spherical Compression of Cannonball Targets with 1.052-µm Laser Beams
Authors: Miyanaga Noriaki , Kato Yoshiaki , Kitagawa Yoneyoshi , Kouketsu Tatsuya , Yoshida Minoru , Nakatsuka Masahiro , Yabe Takashi , Yamanaka Chiyoe
Published: November 2005

The first successful experimental demonstration of spherical implosion of cannonball targets is reported. The cannonball target was irradiated by two 1.052-µm laser beams. The pusher containing DT fuel gas was imploded, with excellent spherical symmetry, by the pressure of the plasma confined between the tamper and the pusher. Both high compression density and high neutron yield were obtained.