bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and Theoretical Trapped Resonance Cone Fields with a Field-Leakage in an Inhomogeneous Magnetoplasma
Authors: Ohnuma Toshiro , Watanabe Tsuguhiro
Published: November 2005

Trapped resonance cone fields with a field-leakage in an inhomogeneous magnetized plasma are confirmed experimentally and numerically near the electron plasma frequency layer.
4–5 µm Emissions from 1.3-µm and 1.5-µm InGaAsP/InP Lasers: Evidence for Excitations in Split-Off Valence Band
Authors: Nonomura Kazuhiro , Suemune Ikuo , Yamanishi Masamichi , Mikoshiba Nobuo
Published: November 2005

4–5 µm wavelength emissions associated with recombinations of holes in the split-off valence band and electrons in the light-hole valence band were observed from 1.3 µm and 1.5 µm InGaAsP/InP lasers. Hole populations in the split-off valence band are dramatically increased with the current level and temperature rise. It was deduced from their current dependence as well as that of acoustic signals so far reported that Auger recombination is a most probable mechanism up to about half of the threshold current, and that intervalence band absorption and its saturation behavior mainly influences the lasing characteristics above that current.
Dependence of T0 on P-Cladding Layer Doping Level in InGaAsP Lasers
Authors: Chen T. R. , Chiu L. C. , Yu K. L. , Koren U. , Hasson A. , Margalit S. , Yariv A.
Published: November 2005

The effects of the doping level in the P-cladding layer on the T
0 of InGaAsP lasers have been investigated. A threshold temperature parameter T
0 as high as 90 K has been observed. A new laser structure which involves a simple modification scheme applicable to most laser structures with improved temperature sensitivity has been demonstrated.
Surface Resonances in GaAs(100) Surface
Authors: Suleman M. , Rashid Y.
Published: November 2005

Low energy region of the secondary yield of GaAs(100) surface contains fine structure which is examined in the differential yield mode. The main peak observed at 16.2 eV for normal incidence (θ=0°) is identified as surface resonance due to simultaneous grazing emergence of (11) diffracted beams. For angles of incidence θ=2° and 3° the main peak splits into a doublet with peak energies at 15.5, 17.3 eV and 15, 18 eV respectively. The additional peaks at 3.7 and 9 eV in the fine structure are believed to be due to plasmon threshold mechanism.
Phonon-Induced Transverse Relaxation in LaF3:Pr3+ Measured by Photon Echoes
Authors: Kohmoto Toshiro , Nakatsuka Hiroki , Matsuoka Masahiro
Published: November 2005

Temperature dependences of backward photon echo intensity have been measured from 5°K to 13°K on the 3P0–3H4 (4778 Å) and 1D2–3H4 (5925 Å) transitions of LaF3:Pr3+. Over six orders of magnitude (on the 3P0–3H4 transition) and three orders of magnitude (on the 1D2–3H4 transition) of the photon echo intensity, the experimental results are explained by the one-phonon process (the direct process) taking into account the energy differences between the echo levels and their adjacent levels. Preliminary measurements have also been made on the 4G7/2–4I9/2 (5221 Å) and 4G5/2–4I9/2 (5775 Å) transitions of LaF3:Nd3+.
Two Dimensional X-Ray Stress/Strain Distribution Meter
Authors: Horiuchi Toshihisa , Okamoto Toshiyuki , Shichijyo Shiro , Takemura Tetuo
Published: November 2005

A rapid measuring system for the stress/strain distribution in a sample has been developed by the use of the position sensitive proportional counter (PSPC) X-ray system and the X-Y scanning system controlled by the computer system. Its performance is demonstrated for the aluminum plate specimen with a central hole under uniaxial tensile stresses. d(422) values of 40×40 points on the specimen have been obtained automatically during about three hours. Furthermore, these data can be transformed to the equi-stress/strain map automatically.
Deep Level Luminescence Ralated to Thermal Donors in Silicon
Authors: Tajima Michio , Stallhofer P. , Huber D.
Published: November 2005

We investigate the origin of the deep level luminescence from Czochralski-grown Si crystals annealed at about 450°C in relation to “thermal donors” (TD's). A sharp line appears at 0.767 eV in luminescence spectra at 4.2 K and 77 K. The appearance condition of this line coincides with that of the TD's. The intensity of the line measured at 77 K reflects the TD concentration. We conclude that the 0.767-eV line is due to a certain form of the oxygen agglomerates transformed from the oxygen complexes responsible for the TD's.
Photoluminescence Related to Dislocations in Annealed Czochralski-Grown Si Crystals
Authors: Tajima Michio , Matsushita Yoshiaki
Published: November 2005

The deep level photoluminescence at 4.2 K and 77 K from annealed Czochralski-grown Si crystals is investigated in relation to dislocations generated during the oxygen precipitation process. The appearance of the “rod-like defects” induces two broad bands at 0.81 and 0.88 eV. The generation of perfect dislocation loops punched out from oxygen precipitates introduces two strong and sharp lines at 0.808 and 0.874 eV. The characteristics of these signals are discussed in comparison with the dislocation-related lines observed in plastically deformed Si crystals.
Heavily Te-Doped GaAs Layers by Plasma-Assisted Epitaxy
Authors: Matsushita Koichi , Sugiyama Yoshihiro , Igarashi Seiji , Hariu Takashi , Shibata Yukio
Published: November 2005

n-type GaAs layers, which were heavily doped with Te above 2×1019 cm-3, were epitaxially grown on (100)GaAs at a substrate temperature around 550°C by plasma-assisted epitaxy. These n+-GaAs layers showed mirror faced surface and their Hall mobilities were about 900 cm2/Vsec. These characteristics were not changed by annealing at 550°C for 10 min. The present technology has potential use for the formation of non-alloyed ohmic contacts.
Amorphous Si/Polycrystalline Si Stacked Solar Cell Having More Than 12% Conversion Efficiency
Authors: Okuda Koji , Okamoto Hiroaki , Hamakawa Yoshihiro
Published: November 2005

A new type of amorphous silicon (a-Si) solar cell stacked with polycrystalline silicon (poly-c-Si) has been developed. The conversion efficiency more than 12% has been obtained with a cell structure of ITO//n-i-p a-Si//n a-Si/p poly c-Si//Al. A series of technical data on the cell fabrication and resulting photovoltaic characteristics are presented.
A New Photoacoustic Method to Characterize Wider-Gap Epitaxial Layers on Narrower-Gap Substrates
Authors: Ohba Yasuo , Mizuta Masashi , Kukimoto Hiroshi
Published: November 2005

A new photoacoustic method is demonstrated to determine the principal band gap energy together with higherlying band edges of thin epitaxial layers of Ga1-x
Al
x
As. The output signal intensity is proportional to an optical absorption coefficient at least to the extent of 104 cm-1; correspondingly, a thickness less than 1 µm of epitaxial layers is detected without any processing of as-grown samples.
A New AsH3 Cracking Method for the MOCVD Growth of InGaAs
Authors: Ogura Mototsugu , Ban Yuzaburoh , Morisaki Motoji , Hase Nobuyasu
Published: November 2005

We have demonstrated the MOCVD growth of InGaAs on an InP substrate under atmospheric pressure by cracking AsH3. The self-cracking system has been employed; AsH3 is introduced by passing near the rf-heated susceptor into the reactor tube, resulting in AsH3 cracking prior to its mixing with triethylindium and triethylgallium source materuals. The typical carrier concentration and Hall mobility obtained are 4.7×1016 cm-3 and 3,050 cm2/Vsec at room temperature, respectively. The half width of the photoluminescence spectrum is as narrow as 19 meV at 77 K. These results are comparable to those of liquid phase epitaxy grown InGaAs.
A New Optical Circuit with a Steric Waveguide Pattern
Authors: Yamada Takeshi , Takato Norio , Kurokawa Takashi
Published: November 2005

Steric optical circuits, with three dimensional arrangement of waveguides with circular cross-section, have been proposed and realized by a stereographic process with use of a photosensitive monomer. They were fabricated by exposing the liquid photosensitive monomer to UV light and simultaneously immersing solidified waveguides into the liquid monomer. A divider and a waveguide array have been fabricated by this method.
Polycrystalline Zn3P2/Indium-Tin Oxide Solar Cells
Authors: Suda Toshikazu , Suzuki Masahisa , Kurita Shoichi
Published: November 2005

Zinc phosphide (Zn3P2)/indium-tin oxide (ITO) heterojunction solar cells are fabricated by rf sputter depositing ITO on large grain polycrystalline Zn3P2 wafers. An AES analysis indicates that sputter etching of the Zn3P2 wafer surface before depositing ITO is of great importance in achieving a better performance as a solar cell. The passivation of Zn3P2 by reaction with atomic hydrogen is found to improve the cell performance significantly. Consequently, a power conversion efficiency of 2.1% (6 mm2 in active area) has been obtained without antireflection coating.
Direct Method with Triangular Waves for Measuring Spontaneous Polarization in Ferroelectric Liquid Crystals
Authors: Miyasato Keita , Abe Shigeharu , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

It is proposed to apply the direct measurement of spontaneous polarization using triangular waves to ferroelectric liquid crystals. The use of the triangular waves allows us to easily subtract the background contribution due to the conductive and the capacitive current and to accurately determine the spontaneous polarization, since a bump due to the polarization realignment appears on a straight base line. Moreover, the experiment with pulsed triangular waves clearly reveals no existence of the threshold voltage for deforming the helix and some characteristic properties of the dynamic reaction of the helix to the field applied.
Solitary Spectral Linewidth and Its Reduction with External Grating Feedback for a 1.55 µm InGaAsP BH Laser
Authors: Olesen Hening , Saito Shigeru , Mukai Takaaki , Saitoh Tadashi , Mikami Osamu
Published: November 2005

Spectral linewidth measurements as a function of normalized pumping rate were performed on a 1.55 µm BH laser using the delayed self-heterodyne method. The solitary laser operated in a single longitudinal mode up to 1.8 times threshold, where the linewidth was measured to be 45 MHz. The experimental results are compared with theoretical calculations of the linewidth contributions due to spontaneous emission and carrier FM noise. Linewidth reduction was achieved by means of optical feedback with an external grating. With a 1 m cavity length the linewidth could be reduced by three orders of magnitude to a minimum of 40 kHz.
Improvement of Schottky MOSFET Characteristics by B+ Implantation in Active Region
Authors: Uehira Kazutake , Kato Kinya , Wada Tsutomu
Published: November 2005

Schottky MOSFETs is effective to prevent latch-up in bulk CMOS due to a low minority carrier injection efficiency. However, the Schottky MOSFETs have a disadvantage of low g

m
, which is due to the offset caused by gaps between the S/D and the inversion layer under the gate electrode. This paper shows that B+ implantation of ∼1011/cm2 in active regions for threshold voltage control in conventional CMOS process improves the g

m
of Schottky p channel MOSFETs. This effect is due to the doped B+ which forms p type layer in the gap regions between the S/D and the inversion layer and eliminates the offset electrically.
Spectrum-Resolved Absolute Energy Measurement of X-Ray Emission in 0.17–1.6 keV Range from a 0.53 µm Laser-Irradiated Au Target
Authors: Okada Kazuyuki , Mochizuki Takayasu , Hamada Munemitsu , Ikeda Naoaki , Shiraga Hiroyuki , Yabe Takashi , Yamanaka Chiyoe
Published: November 2005

Spectrum-resolved absolute X-ray radiant energy emitted from 0.53 µm laser-irradiated planar Au plasmas was measured in the 0.17–1.6 keV range. The obtained spectral shape was found to considerably deviate from a blackbody spectrum. The conversion efficiency from the incident laser energy to radiant energy was investigated at the laser intensity range of 2×1013∼2×1015 W/cm2 with a nominal laser incident angle of 54° and determined to be 43% ± 13% for 1.0 nsec pulse and 20% ± 3% for 0.25 nsec at I
L∼1014 W/cm2. The radiant energy above 1.6 keV was less than 1% of the incident laser energy.
X-ray Diffraction Topographic Observation of Si Single Crystals Irradiated with 150 MeV Ni+9 and Cl+9 Ions
Authors: Tomimitsu Hiroshi
Published: November 2005

For Si single crystals irradiated with 150 MeV Ni+9 and Cl+9 ions, it was found by X-ray diffraction topographic observation that (1) two kinds of characteristic and systematic fringes can be seen in the irradiated area, (2) the surface of the specimen irradiated with Cl+9 was most damaged just behind the Al-mask of 34 µm thickness, rather than the directly irradiated area, and (3) the specimen is deformed after the irradiation and lattice strains are concentrated at the irradiation boundaries. The deformation and the strains were observed on the reverse surface of the irradiated crystal.
Low Resistance Al/Si Ohmic Contacts on Boron Implanted Shallow p+ Si Layers Formed by Halogen Lamp Annealing
Authors: Hara Tohru , Ohtsuka Noboru , Enomoto Syuichi , Hirayama Takeshi , Amemiya Kimio , Furukawa Masakazu
Published: November 2005

Contact resistance of Al/Si Ohmic electrodes formed on boron implanted shallow p+ layers has been measured, where the annealing of ion implanted layers was performed by halogen lamp rapid heating at different temperatures ranging from 900°C to 1100°C. Contact resistance decreases gently with increasing temperature and becomes constant at above 950°C. Specific contact resistance of 1.5×10-7 Ohm-cm2 was attained at doses above 4×1015 cm-2 and at temperatures above 950°C. This value is very low and more than one order lower than that obtained by conventional furnace annealing. This contact is useful technology to fabricate high density and high speed MOS LSI.
Electron Thermal Diffusivity in JFT-2 Tokamak with NBI Heating
Authors: Okamoto Masao , Yamamoto Shin , Shimizu Katsuhiro , Maeno Masaki , Sengoku Seio , Yamauchi Toshihiko , Miura Yukitoshi , Matsumoto Hiroshi , Ohtsuka Hideo , Tani Keiji
Published: November 2005

By solving the energy balance equations, the electron thermal diffusivity χeNBIis estimated for experimental data from the JFT-2 tokamak with neutral beam injection heating. Heat deposition profiles from fast ions to bulk electrons and ions are calculated in detail by an orbit-Monte-Carlo code including a scrape-off plasma. The increase in density and temperatures near scrape-off layer is supposed to worsen the deposition profile and the estimated χeNBIis two to three times that in the Ohmic case without additional heating.
Magnetic Domains of Single-Domain Particles of SmCo5 Observed by the Colloid-SEM Method
Authors: Inoue Tetsuo , Goto Kimiyoshi , Sakurai Tomoaki
Published: November 2005

Magnetic domains of ball-milled small particles of the SmCo5 phase below several microns in size have been observed by the colloid-SEM (scanning electron microscope) method, a modified Bitter method. Domains on the c plane of single-domain particles were found when the particle size decreased. Measurements show that sizes of two single-domain particles are 2.2 and 1.6 µm. These values are discussed with the theoretical critical sizes for the single-domain particles of SmCo5.
Hole Mobilities of Graphoepitaxy Poly-Si Devices
Authors: Kobayashi Keiji
Published: November 2005

Graphoepitaxy P-channel poly Si FETs were fabricated in 0.9 µm thick, LP-CVD poly-Si on 0.3 µm thick SiO2 on Si(100) wafer. Grooves 2, 5, 10 µm in width and 300 Å in depth were photolithographically defined on the SiO2 film. Poly-Si layers were annealed by CW-Ar laser with a power of 10 W. Field effect hole mobilities in the poly-Si FETs were in the range of 25∼110 cm2/V·sec. The grain size of graphoepitaxy laser annealed poly-Si varied from 0.7 µm to 2.5 µm. The increase of hole mobilities in poly-Si devices is attributed to the increase of grain size.
Electrochemical Preparation of Polyselenophene and Its Property
Authors: Yoshino Katsumi , Kaneto Keiichi , Inoue Shigehito , Tsukagoshi Kunimitsu
Published: November 2005

A new conducting polymer, polyselenophene film is prepared by electrochemical polymerization. A band gap of undoped polyselenophene is evaluated as 1.95 eV and its conductivity is around 10-9 S/cm at room temperature. The absorption spectrum changes remarkably, by the doping of acceptor like ClO4, and also the conductivity increases to 10-4 S/cm.
Performance of a Diverged Electron Beam Ion Diode
Authors: Miyamoto Shuji , Yoshinouchi Atushi , Ozaki Tetu , Higaki Satoshi , Fujita Hirokazu , Imasaki Kazuo , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

The experimental performance of a diverged electron beam ion diode, high brightness and high efficiency light ion diode for inertial confinement fusion, is presented. Diode brightness of 1.4 TW/cm2rad2 and ion efficiency up to 20% was obtained in 5 Ω diode operation. Experimental results were scaled to low impedance operation with further high brightness and high efficiency ion diode.
A Large Barrier Height Schottky Contact between Amorphous Si–Ge–B and GaAs
Authors: Suzuki Masamitsu , Murase Katsumi , Asai Kazuyoshi , Kurumada Katsuhiko
Published: November 2005

Electrical properties of contacts between amorphous Si–Ge–B and GaAs are studied. A Schottky contact with a barrier height as large as 0.99 V has been realized. The barrier height can be varied by changing the composition of the amorphous films. Amorphous Si–Ge–B is applied to GaAs FETs as gate electrodes. A large saturated drain current of 900 µA/10 µm gate width has been realized. This value is 1.88 times as large as conventional normally-off GaAs MESFETs.
Microstructures and Hydrogen Bonding Environments of a-Si: H Films Prepared by RF Sputtering in Pure Hydrogen
Authors: Ishida Hiroyuki , Noda Mikio , Shimizu Hideki
Published: November 2005

Microstructures and correlated hydrogen bonding environments of a-Si: H films prepared by RF sputtering in pure hydrogen are investigated by TEM, FT-IR and optical absorption measurements. The films are more homogeneous than those prepared in an Ar/H2 mixture; they are composed of fine grains and tend to have a microcrystalline structure with increasing gas pressure. Configurations of SiH2 and SiH3 increase with increasing voids, indicating that these are formed in the void regions on the surface of the grains. From these results, the roles of argon and hydrogen correlated to the microstructure of the films are discussed.
An Interpretation of Shear Elastic Behaviour in the Cholesteric Phase Observed by Ultrasonic Measurements
Authors: Kawamura Yasuaki , Okano Koji
Published: November 2005

A torsional quartz crystal method was used to obtain the complex shear mechanical impedance of cholesteryl nonanoate at 150 kHz. The apparent shear modulus evaluated from the measured impedance shows a finite value of ∼104 cgs in the middle of the cholesteric phase. The observed shear elastic behaviour can be interpreted in terms of the existence of an apparent layer compression modulus in the cholesteric phase, which gives rise to the second sound mode similar to that in the smectic A phase.
Development of Multihundredjoule HF (H2/SF6) Chemical Lasers Initiated by Intense Electron Beams
Authors: Kannari Fumihiko , Suzuki Tadashi , Obara Minoru , Fujioka Tomoo
Published: November 2005

The development of an electron-beam initiated HF (H2/SF6) laser is described. Typical parameters of the circular electron beam used in the experiment are 2 MeV, 80 kA, 65 ns (FWHM), and 9 cm in diameter. The maximum laser energy of 250 J in a 70 ns FWHM pulse is obtained with an electrical efficiency of 8.3% at SF6/H_2=200/2 (Torr). Initiation parameters are determined by theoretical HF laser simulation, such that the dissociation rate, the energy cost per F atom and the chemical efficiency are 3%, 6.5 eV/F, and 39%, respectively.
Hundredjoule-Level KrF Lasers Excited Longitudinally by an Intense Electron Beam
Authors: Kannari Fumihiko , Obara Minoru , Fujioka Tomoo
Published: November 2005

Using longitudinally electron-beam excited mixture of argon, krypton, and fluorine, 115 J (9.95 J/l) of the KrF laser energy with a pulse width of 45 ns was obtained with an intrinsic efficiency of 4%. The corresponding peak power was 2.56 GW. Maximum energy was obtained using a 1.25-atm mixture of Ar/Kr/F2
=89.4/10/0.6(%).
Evaluation of Fermi-Level in Doped Films of a-SiC:H by X-Ray Photoemission Spectroscopy
Authors: Fukada Noboru , Fukushima Yoshito , Imura Takeshi , Hiraki Akio
Published: November 2005

Binding energies of Si 2p core electrons in X-ray photoemission spectra were measured to evaluate Fermi-level of doped films of a-SiC:H with a constant carbon/silicon ratio. Fermi-level of the p-type films deposited under different conditions depended only upon the concentration of boron, determined by secondary ion mass spectroscopy. The comparison between Fermi-level and the activation energy of electrical conductivity showed that the carrier transport in p-type a-SiC:H does not take place at the valence band edge but at the band tail.
Laser Induced Local Etching of Gallium Arsenide in Gas Atmosphere
Authors: Takai Mikio , Tokuda Jun , Nakai Hiroyuki , Gamo Kenji , Namba Susumu
Published: November 2005

Pyrolytic local etching of GaAs using focussed Ar laser beams in CCl4 gas atmosphere was performed to investigate the possibility of maskless etching processes by laser beams. Etching was found to take place only for the laser-irradiated area and etching rates from 0.3 to 40 µm/scan with an etched linewidth from 7 to 70 µm were obtained at CCl4 pressure of 80 Torr. A carbon line buried in GaAs was, for the first time, obtained for a single scan of a laser beam with low scanning speeds.
Photoelectric Effects on Doped Semiconductor/MBBA/SnO2 Cell
Authors: Yatsuzuka Kyoko , Watanabe Akira
Published: November 2005

The photoelectric effects at the doped semiconductor/MBBA interface have been studied and a model is proposed. The injected charges from electrodes into MBBA form a space-charge distribution and the energy band in the semiconductor bends near this interface, so that photo-injected carriers in MBBA are conveyed to achieve a new equilibrium. From the peak shift in spectral response caused by insertion of the MBBA layer between semiconductor and metal plates, the activation energy of 0.4 eV is calculated. This value coincides with the activation energy for the π-electron hopping process between benzene molecules.
High Impurity Doping in Si-MBE Using Liquid Ga Ion Source
Authors: Sakamoto Tsunenori , Komuro Masanori
Published: November 2005

Low-energy implantation doping techniques in Si-MBE using a liquid metal ion source of Ga are reported. Ga ions accelerated up to 500 V or 1000 V are projected onto the MBE layer during film growths, where substrate temperatures range from 550°C to 1100°C. The maximum carrier concentration of 1×1019 cm-3 is obtained under the conditions of ∼800°C at the accelerating voltage of 500 V. This value is 5 or 100 times as high as cases of partial ionization or thermal evaporation of Ga, respectively. Below ∼800°C, the carrier concentration is strongly ruled by the solid solubility. At higher temperatures, the rapid decrease of incorporation is observed, which is probably caused by re-evaporation of the implanted Ga atoms.
ESR Studies of Geothermal Boring Cores at Hachobara Power Station
Authors: Ikeya Motoji
Published: November 2005

Electron spin resonance (ESR) dating of a boring core down to the depth of 800 m at Hachobara Geothermal Power Station has been made utilizing signals of defects produced by natural radiation. The lifetime and the growth of a defect at a geothermal temperature are estimated theoretically from the annealing temperature. Tentative ESR ages at several depths using signals at g=2.0060 and g=2.0010 presumably due to E1 and E' centers are interpreted taking the lifetimes at the temperature into account. Organic methanol found by irradiation of cores may be condensed by natural distillation in a geothermal field.
ESR Study on E'-Centers Induced by Optical Fiber Drawing Process
Authors: Hibino Yoshinori , Hanafusa Hiroaki
Published: November 2005

The optical fiber drawing process has been found to produce defect centers. E'-centers induced by the drawing process were observed in both pure silica and GeO2-doped silica fibers using electron spin resonance techniques. The E'-center concentration increases with both drawing velocity and temperature at the preform neckdown region.
Non-LTE Analysis of Soft X-Ray Spectrum from Laser-Irradiated Gold Plasma
Authors: Kiyokawa Shuji , Yabe Takashi , Mochizuki Takayasu
Published: November 2005

Soft X-ray spectrum from laser-irradiated Au plasma is analyzed by 1-D hydrodynamic Lagrangian code with a non-LTE model and a multi-group radiation transport code and is compared with the experimental results. The physical meaning of the experimentally obtained spectrum is clarified and the total emitted power density proves to have maximum value at a certain combination of ion density and electron temperature.
Crystalline Defects in Selectively Epitaxial Silicon Layers
Authors: Kitajima Hiroshi , Ishitani Akihiko , Endo Nobuhiro , Tanno Kohetsu
Published: November 2005

Crystalline defects in selectively epitaxial silicon layers have been studied as a function of growth parameters, especially growth temperature and HCl flow rate injected in the SiH2Cl2–H2 system, for (100)- and (111)-substrates. Defects, which were mostly pairs of stacking faults, were observed along the sidewall. The defect density in the epitaxial layer decreased with both increasing HCl flow rate and decreasing growth temperature. Electrical property of the epitaxial layer was also improved with decreasing growth temperature.
Anomalous Transmission of Laser Light through a Thin Foil Target under 1.06 µm Laser Irradiation
Authors: Nishimura Hiroaki , Yamada Kawakatsu , Yagi Makoto , Matsuoka Fushiki , Nishihara Katsunobu , Yamanaka Tatsuhiko , Yamanaka Chiyoe
Published: November 2005

We investigated the anomalous laser light transmission phenomenon by means of optical backlighting and sideward shadowgraphy as well as the calorimeteric and spectroscopic measurements of transmitted light. These experimental data and relevant numerical simulation suggest that the evaporation of the target material by the amplified spontaneous emission of the laser system is one of the feasible factors in this effect.
Light Ion Beam Transport in a Multi-Plasma Channel System
Authors: Ozaki Tetsu , Yoshinouchi Atsushi , Imasaki Kazuo , Miyamoto Shuji , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

The beam overlap in a multi-plasma channel was studied. A triple wire-exploding channel was formed as a simulational model of an overlap channel system. Post-transported beam particles in the channel overlap region were observed by a pinhole shadow box as a function of the particle energy. Beam expansion and beam deflection in the overlap region could be suppressed when channels and return paths were alternately arranged.
Dependence of the Mobility and the Concentration of Two-Dimensional Electron Gas in Selectively Doped GaAs/N-AlxGa1-xAs Heterostructure on the AlAs Mole Fraction
Authors: Saito Junji , Nanbu Kazuo , Ishikawa Tomonori , Hiyamizu Satoshi
Published: November 2005

The mobility and the concentration of two-dimensional electron gas (2DEG) were measured by Hall measurements (4.2 K, 77 K) and Shubnikov-de Haas measurements (4.2 K) in selectively doped GaAs/N–Al
x
Ga1-x
As (0.1≦x≦0.4) heterostructures grown by MBE. The electron conduction in the Si-doped N–Al
x
Ga1-x
As layer was eliminated by careful step etching of this layer. When x was increased from 0.1, the 2DEG mobility considerably increased, and it reached a maximum mobility (243,000 cm2/Vs at 4.2 K; 107,000 cm2/Vs at 77 K) at x=0.25-0.3. However, the sheet electron concentration of 2DEG was not sensitive to x, and showed broad peak (6×1011 cm-2) at around x=0.25.
Photo-Chemical Vapor Deposition of Silicon Nitride Film by Direct Photolysis
Authors: Numasawa Youichirou , Yamazaki Kouji , Hamano Kuniyuki
Published: November 2005

Silicon nitride film was deposited onto a silicon substrate using a photo-CVD (chemical vapor deposition) technique, which is based on direct photolysis of SiH4/NH3 gas mixture by 185 nm ultraviolet light from a mercury lamp. Deposition rate of 10 nm/minute was achieved without using any photo-sensitizer such as mercury vapor with a photo-CVD system developed for this direct photolysis. Infrared absorption spectrum, Auger spectrum, refractive index and etch rate in buffered HF solution were measured on the deposited film. It was revealed that the film contains 1.4×1022 cm-3 of hydrogen atoms and is nitrogen-rich in its composition. Breakdown field strength, leakage current and surface charge density characteristics were superior to those of conventional plasma-CVD silicon nitride film.
Effect of Operating Pressure on the Properties of GaAs Grown by Low-Pressure MOCVD
Authors: Takagishi Shigenori , Mori Hideki
Published: November 2005

Undoped GaAs epitaxial layers were grown by low-pressure MOCVD in a wide range of operating pressure (3×10-3 to 75 Torr). These epitaxial layers had smooth surfaces. Conductivity of the epitaxial layers grown under the same [AsH3]/[TMG] ratio (=75) changed from n-type to p-type at about 5×10-1 Torr as operating pressure was reduced. Low temperature photoluminescence spectra indicate that carbon is the dominant acceptor and its concentration increases as operating pressure is reduced.
Spontaneous Emission Characteristics of Quantum Well Lasers in Strong Magnetic Fields –An Approach to Quantum-Well-Box Light Source–
Authors: Arakawa Yasuhiko , Sakaki Hiroyuki , Nishioka Masao , Okamoto Hiroshi , Miura Noboru
Published: November 2005

Characteristics of a GaAs/AlGaAs quantum well (QW) laser diode are studied for the first time under strong magnetic fields up to 30 Tesla. When field normal to QW plane is increased, the spontaneous emission spectrum is found to shift toward the higher photon energy, following the shift \hbarωc/2 of the lowest Landau level in the region of strong magnetic fields. Moreover, the emission spectrum is shown to be very little affected when magnetic fields are applied parallel to the QW plane. These results give evidence of light emission from a fully-quantized zero-dimensional carrier system in GaAs QW structures with strong magnetic fields normal to the QW plane.
Effects of Electrons Ejected from the Substrate on PGMA Negative Resist Cross-Linking in X-Ray Lithography
Authors: Okada Koichi , Matsui Junji
Published: November 2005

Effects of electrons ejected from the substrate on poly (glycidyl methacrylate) (PGMA) cross-linking have been experimentally studied by comparing sensitivity characteristics obtained using Pd, Mo, Si and Al X-ray sources. In the Al, Si or SiO2 substrate, remaining PGMA film thicknesses, measured at the gel-point X-ray dose obtained with the AZ-1450 J substrate, have been compared for the above 4 X-ray sources. It was found that the remaining film thicknesses were in the 100–500 A range. It was also found that fairly close correlation exists between the remaining film thickness and the absorption coefficient for the substrate.
Investigation of GaAs Surface Morphology Induced by Cl2 Gas Reactive Ion Beam Etching
Authors: Sugata Sumio , Asakawa Kiyoshi
Published: November 2005

GaAs surface morphology, induced by a new reactive ion beam etching (RIBE) system using a Cl2 gas, has been investigated with scanning electron microscopy (SEM) and laser Raman spectroscopy. Appearance of the TO phonon peak in the Raman spectrum was found to be available for recognizing the surface roughness, which strongly depends on the etching parameters such as an ion extraction voltage (Ve) and a gas pressure (Pg). Rough surface caused at the higher Ve and the lower Pg, say, 500 V and 4×10-4 Torr, respectively, has been made very smooth by increasing the gas pressure to, say, 2×10-3 Torr.
A Practical Method of Preparing Thin Homogeneous Ferroelectric Smectic Cells for Electro-Optical Microsecond Switches: Alignment Control of Liquid Crystal Molecules by Utilizing Spacer Edges
Authors: Kondo Katsumi , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

A new method has been described for preparing a homogeneous monodomain cell with the non-treated clean surfaces. The method relies on the alignment control of liquid crystal molecules at the spacer edges and is particularly simple and convenient. The growing process and the resultant homogeneous monodomain have been shown for the parallel molecular alignment at the edge of a polyethylene terephthalate film cut along the main drawing direction. The possibility of the perpendicular alignment at the spacer edges has also been pointed out by observing that the molecules align perpendicularly at the interface to air.
Soft X-Ray Driven Ablation and Its Positive Use for a New Efficient Acceleration
Authors: Yabe Takashi , Kiyokawa Shuji , Mochizuki Takayasu , Sakabe Shuji , Yamanaka Chiyoe
Published: November 2005

The ablation process driven by soft X-ray is investigated by one-dimensional hydrodynamic code coupled with LTE, average ion model and multi-group radiation package. The following two major results are obtained: (1) the ablation pressure and mass ablation rate scalings, and (2) a new acceleration scheme which positively uses the unique property of soft X-ray transport.
Electron Irradiation Induced Amorphization at Dislocations in NiTi
Authors: Mori Hirotaro , Fujita Hiroshi , Fujita Makoto
Published: November 2005

Process of the crystalline-amorphous transition in NiTi induced by electron irradiation has been investigated by a combination of high voltage and conventional electron microscopy, with emphasis on the study of the initiation sites of the transition. At the beginning stage of irradiation, a localized amorphization takes place at dislocations so that a cylindrical amorphous region is formed along individual dislocation lines. Continued irradiation brings about the lateral growth of the cylindrical amorphous regions. This is the first time such a preferential transition at dislocations has been observed in metal crystals.
Space Overshoot of Photoexcited Electron Drift Velocity in Germanium Calculated by a Particle Number Varying Monte Carlo Method
Authors: Matsumoto Kiyoshi , Ozaki Hajime
Published: November 2005

The space overshoot of photoexcited electron drift velocity in germanium has been investigated by the “particle number varying Monte Carlo method”. It was found that in spite of the spatially distributed photogeneration of electrons, a remarkable space overshoot of drift velocity can appear in a region approximately the inverse number of the absorption coefficient distant from the cathode.
Josephson NOR Decoder Circuit for Josephson Memory Arrays
Authors: Nakanishi Takuji , Fujita Shuichi
Published: November 2005

A new type of Josephson decoder circuit has been devised and designed. The fundamental operation principles for the circuit are based on modification of the address signal multiplicand A0·A1·...·A
n
to NOR form. Implementation of this principle gives large operation margins and high operation speed. In building the decoder, a new large fan-out gate, inverter circuit and timed bias circuit were devised. Proper operation of the decoder was confirmed by computer simulations, and the operation times for the 5-to-32 decoder obtained were about 300 ps for nominal conditions and 50 ps for the best conditions. The designed operation bias margin for the decoder is ±37%.
Elastooptic and Electrooptic Properties of GaAs
Authors: Suzuki Nobuo , Tada Kunio
Published: November 2005

The spectral dispersions of the elastooptic and the linear electrooptic coefficients of GaAs in the wavelength region λ0=1.06–1.50 µm have been measured accurately. In this wavelength region, the elastooptic coefficients, p
11, p
12, and p
44, range from -0.02 to -0.18, while the linear electrooptic coefficients, r
41
T and r
41
S, range from -1.17×10-12 m/V to -1.53×10-12 m/V. The Faust-Henry coefficient C of GaAs (n\lesssim1016 cm-3) at λ0=1.06 µm has been determined as -0.51 from Raman scattering measurements.
Real-Time Observation of Picosecond Pulse Compression by Saturable Absorber
Authors: Gima Toshiaki , Uchiki Hisao , Kobayashi Takayoshi
Published: November 2005

The amplified picosecond pulses of a dye laser synchronously pumped by a mode-locked Ar+ laser were compressed by a saturable absorber (DODCI). The deformation of the pulses was studied by real-time observation. The incident and output pulse shapes were observed simultaneously and compared with each other in single-shot experiments using a streak camera. The shape of the deformed and compressed pulse obtained by numerical calculation on a model based on a “two-level” approximation agreed well with the observed shape of the output pulse.
Magnetothermal Characteristics of Rapidly-Quenched Fe–Si Magnetic Powder
Authors: Enokizono Masato , Narita Kenji
Published: November 2005

For this investigation, the Si–Fe powder containing 1% to 6.5% silicon was prepared by the spark erosion technique, which has a higher quenching rate than splat-cooling. The roughly spherical powder particles of 6.5% Si–Fe ranged from 0.1 µm to 30 µm in diameter, and the rapidly quenched magnetic powder was composed of both noncrystalline and crystalline portions. The fractional volume of the noncrystalline portion increased as the particle size decreased. The procedure for preparing the powder, its magnetothermal characteristics and its crystallization behaviour are discussed.
Magnetoelastic Oscillations of a Bloch Wall in Ferromagnets with Dissipation
Authors: Motogi Shinya , Maugin Gérard A.
Published: November 2005

Magnetoelastic oscillations of a Bloch wall are investigated theoretically. The viscosity of the material and the spin damping are taken into account in their rotationally invariant form. It is shown that the solid viscosity affects not only the generated-sound spectrum but also the resonance spectrum of wall oscillations. The nominal effect of the viscosity is coupled with the static and dynamic magnetoelastic interactions.
Slow Surface Wave Propagation in an Azimuthally-Magnetized Millimeter-Wave Solid-Plasma Coaxial Waveguide
Authors: Obunai Tetsuo , Hakamada Katsuhiro
Published: November 2005

The propagation characteristics in an azimuthally-magnetized partially-filled solid-plasma coaxial waveguide using n-type InSb at 77 K as the plasma material have been analyzed theoretically and calculated numerically. The results are compared with those for parallel-plate plasma waveguide studied previously. When the proper cross-sectional configuration and field parameters are employed, slow surface wave resonance takes place in the waveguide and a much slower wave propagation velocity at a reduced resonant magnetic field is obtained.
Operational Characteristics of a Tunable Single-Mode Injection-Locked TEA CO2 Laser
Authors: Okada Tatsuo , Nishimura Fumiyuki , Inoue Shuki , Muraoka Katsunori , Akazaki Masanori
Published: November 2005

A high-power, tunable, single-mode TEA CO2 laser has been developed using injection-locking for the pumping source of a submillimeter laser. A tunability of over 1.5 GHz around the line center has been achieved with an output energy of 30 J, by using an etalon-tuned TEA CO2 laser as an injection source. In addition, the injected operation showed suppression of the gain-switched spike of the usual free-running TEA CO2 laser, and yielded an elongation of the pulse duration up to 500 ns (FWHM). A simple model describing the temporal properties of tunable injection-locked operation is presented, and the estimated tunable range based on the model is in good agreement with the experimental result.
A Solar-Pumped cw 18 W Nd:YAG Laser
Authors: Arashi Haruo , Oka Yasuo , Sasahara Nenokichi , Kaimai Atsushi , Ishigame Mareo
Published: November 2005

The development of a solar-pumped Nd:YAG laser is reported. A solar energy collector consisting of a paraboloidal mirror 10 m in aperture and 3.2 m in focal length is used to pump a water-cooled Nd:YAG laser rod 4 mm in diameter and 75 mm in length. The maximum output of the laser is 18 W in multi-mode, the highest output power reported so far in solar-pumped lasers. Further improvements designed to increase the power are also discussed.
A Study on the Electrical Properties of the Compressed CdSe and (CdSe)1-xZnx Powders
Authors: Kim S. U. , Park M. J.
Published: November 2005

The electrical properties of CdSe and (CdSe)1-x
Zn
x
(x=0.03, 0.05, 0.1, 0.3, 0.5 mole fractions, respectively) have been investigated in the compressed powder form. The synthesis of CdSe is also studied experimentally. It is found that the dc conductivities of the compressed powders have the amorphous like properties fitting to the Davis-Mott's theory. The (CdSe)1-x
Zn
x
samples have been prepared for the measurement of the dc conductivities by melting the samples under the condition of the 3 atm argon pressure. The conductivity curves have shown the semiconducting behaviour above approximate 230 K and the metallic behaviour below 230 K, likely the Anderson transition.
Optimum B+ Dose in S/D Regions to Improve Schottky p-Channel MOSFET Characteristics
Authors: Uehira Kazutake , Kato Kinya , Wada Tsutomu
Published: November 2005

A major disadvantage of Schottky MOSFETs is that g

m
is very low in comparison with conventional MOSFETs. Forming the p layer in S/D regions by B+ implantation increases the value of g

m
in a Schottky p-channel MOSFET. However, too great a B+ dose cannot maintain the Schottky MOSFET's advantages of latch-up prevention and restriction of the short-channel effect, because it changes the S/D into a pn junction from the Schottky junction. Also, too small a B+ dose does not give the maximum possible improvement in g

m
. This paper presents the optimum B+ dose in the S/D regions for giving the maximum improvement in g

m
without sacrificing the advantages of the Schottky MOSFET. Experiments on the dependence of g

m
the short-channel effect, and the latch-up characteristics on the B+ dose in the S/D regions show that the optimum B+ dose is near 1012 cm-2.
Mechanisms of Mo or Mo-Silicide/n+-Si Ohmic Contact Degradation Induced by High-Temperature Annealing
Authors: Higuchi Kohei , Okabayashi Hidekazu , Kanamori Masaru
Published: November 2005

The degradation modes and mechanisms for Mo or Mo-silicide/n+-Si ohmic contacts induced by high-temperature annealing have been clarified and are classified as follows. 1) High resistance or insulating characteristics are due to oxygen contamination originating from contamination during electrode film deposition, adsorption in an electrode film from the atmosphere and knocked-on oxygen in silicon due to high-dose ion implantation through oxide for the formation of the doped region. 2) Current-flow induced open circuits at partial film cracks along the contact periphery. The film cracks result from volume shrinkage due to silicidation when the oxygen contamination is less severe. 3) Schottky barrier-like properties induced by dopant outdiffusion through silicide.
RF Field Distributions in a Slotted-Type Lisitano Coil
Authors: Suetsugu Yusuke , Kawai Yoshinobu
Published: November 2005

The field distributions in a slotted-type Lisitano coil are analyzed using a simple antenna model, and the microwave power is theoretically found to be supplied near the center of the coil. Field intensities in the Lisitano coil measured with a calibrated loop antenna are compared with the theoretical values, and results supporting the analysis are obtained. The field distributions in a vacuum chamber were also measured.
Numerical Studies on Ergodization Effect of Externally-Applied Helical Field
Authors: Yamada Hiroshi , Yoshida Zensho , Inoue Nobuyuki , Uchida Taijiro
Published: November 2005

The ergodization effect of externally-applied helical perturbations has been studied numerically using a field-line tracing code. The results from the numerical studies account well for experimental observations in the TORIUT-4M tokamak. When a non-resonant helical perturbation is applied to a plasma in the low-qregime, the (2.1) magnetic islands are shown to be ergodized and removed from the plasma periphery. Magnetic surfaces in the central region withq<2, however, are not ergodized, and retain their order.
A Non-Destructive Method for Determining the Distribution of Soil Water Content by Measuring Fast Neutron Transmission Using an NE-213 Organic Scintillator
Authors: Ohnuki Toshihiko , Yamamoto Tadatoshi , Wadachi Yoshiki
Published: November 2005

A method of measuring the water content distribution in a soil layer packed in a column, using fast neutron transmission, has been developed. The calibration curve of the water content was obtained from the rate of decrease of fast neutrons per unit of water content. An NE-213 organic scintillator (2'' in diameter × 2'' in length) and Cf-252(273 µCi) were used as the fast neutron detector and neutron source respectively. The distribution curve of soil water content obtained by the present method was consistent with that obtained by the destructive drying method. The NE-213 scintillator was superior to other conventional detectors (3He, BF3 counter) in measurement accuracy, spatial resolution and measurement sensitivity. The relative error and sensitivity of the present method are discussed in detail in this report.
Single-Crystal Growth of Perovskite-Type La1-xSrxMO3 (M=Fe, Co) Solid Solutions
Authors: Matsuura Takashi , Ishigaki Takamasa , Mizusaki Junichiro , Yamauchi Shigeru , Fueki Kazuo
Published: November 2005

Single crystals of the perovskite-type solid solutions La1-x
Sr
x
FeO3 with x=0.0, 0.1, 0.25 and 0.4 and La1-x
Sr
x
CoO3 with x=0.0, 0.02 and 0.1 were grown by the floating-zone method using an Xe arc-lamp imaging furnace. Under the optimum conditions, single crystals about 5 mm in diameter and 40 mm in length were obtained. High-power X-ray diffraction analysis, optical microscopy and SEM-XMA showed the crystals to consist of a single phase and the distribution of the metal elements to be uniform. Preparation of raw material with precise composition was crucial for the synthesis of the single crystals. In the case of La1-x
Sr
x
CoO3 with x=0.2 and 0.3, CoO and a K2NiF4-type (La1-y
Sr
y
)2CoO4 phase were observed in the perovskite-type solid solutions.
Conditions for OMVPE Growth of GaInAsP/InP Crystal
Authors: Sugou Shigeo , Kameyama Atsuhi , Miyamoto Yasuyuki , Furuya Kazuhito , Suematsu Yasuharu
Published: November 2005

The conditions required for the growth of GaInAsP/InP by organometallic vapor-phase epitaxy (OMVPE) covering the available bandgap wavelength of 1.3–1.6 µm were obtained experimentally with a carefully-arranged experimental set-up. The precision required in controlling the gas flows and temperatures for lattice matching is discussed. The relations between alloy compositions and source gas flow ratios were investigated, as well as p-n junctions. Lasing operation at a wavelength of 1.58 µm was achieved with GaInAsP/InP grown under these growth conditions.
Martensitic Transformation in La1-xSrxCoO3
Authors: Matsuura Takashi , Mizusaki Junichiro , Yamauchi Shigeru , Fueki Kazuo
Published: November 2005

A multiple twin structure was found in single crystals of La1-x
Sr
x
CoO3 (x=0.0, 0.02 and 0.1) by means of an optical microscope and SEM. The width of each domain is about 1∼10 µm. Doubled or quadrupled splitting in Laue spots was observed. The twin structure was explained by a martensitic transformation due to a small rhombohedral distortion. The observed angles and directions of the splitting agreed well with the calculated values. The twin planes were {100} and {110} in the pseudocubic cell. Observation by means of high-temperature optical microscopy revealed that the twin structure did not disappear up to 1000°C. The transformation in La1-x
Sr
x
CoO3 is discussed by comparing it with those in LaAlO3 and NiO.