bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and Electrical Properies of Photo-CVD Silicon Nitride Film
Authors: Hamano Kuniyuki , Numazawa Yoichiro , Yamazaki Koji
Published: November 2005

Silicon nitride film was deposited by mercury-sensitized photochemical vapor deposition (photo-CVD) utilizing a gaseous mixture of SiH4 and NH3 under 253.7 nm ultraviolet light irradiation. The structural and electrical properties of the film were then evaluated with emphasis on the substrate temperature dependence. The film contains a considerable amount of hydrogen, and less dense than silicon nitride film deposited by high-temperature chemical vapor deposition. The structural properties of photo-CVD silicon nitride film are basically similar to those of silicon nitride film deposited by plasma-enhanced chemical vapor deposition (P-CVD). However, the film has better insulating properties than P-CVD film, with a smaller leakage current, a higher breakdown field and a smaller positive charge density within the film.
3D-Computer Simulation of Ion-Beam Deflection Caused by the Displacement of Extraction Electrodes
Authors: Ota Kanji , Inoue Nobuyuki , Nihei Hitoshi , Morikawa Junji , Ishida Shin'ichi , Uchida Taijiro
Published: November 2005

A three-dimensional simulation code for ion-beam formation has been developed for the quantitative evaluation of the beamlet deflection arising from the displacement of the extraction electrode. The code gives a good simulation of the experimentally-observed relations between the deflection angle of the beamlet and the mutual displacement among the extraction electrodes.
Effect of Substrate Temperature on Properties of Glow-Discharged Hydrogenated Amorphous Silicon
Authors: Shirafuji Junji , Kuwagaki Mamoru , Sato Taka'aki , Inuishi Yoshio
Published: November 2005

The substrate temperature dependence of the transport and photoelectric properties of glow-discharged hydrogenated amorphous silicon films has been studied in connection with the morphological heterogeneity in the films. The electron drift mobility at room temperature determined by the time-of-flight method increases exponentially as the substrate temperature is raised, and is possibly associated with the formation of a percolation path through the growth of small quasi-crystalline zones. In contrast with the exponential increase in the electron mobility, the lifetime, or the deep-level trapping time, of electrons shows a maximum at a substrate temperature of 200°C, in parallel with the ESR spin density and tail-to-tail luminescence intensity.
Impurity Effects in Chalcogenide Amorphous Semiconductors by Low-Temperature Diffusion of Metal Ions
Authors: Okano Shuichi , Suzuki Akio , Fukada Noboru , Imura Takeshi , Hiraki Akio
Published: November 2005

Cu and Cd ions were found to diffuse into a-As2Se1Te2 films below the glass transition temperature. Cu-doped samples exhibited p-type conduction, while Cd-doped samples exhibited n-type conduction, and the conductivity of the sample films doped with these metal ions increased with the impurity content. Activation-type conduction was dominant over a wide temperature range even in heavily-doped samples, and the band-gap shrinkage due to doping with impurities was small compared with the decrease in the activation energy for conduction. The strong impurity effects are thus considered to be caused not by an increase in the portion of hopping conduction through defect states but by a shift in the Fermi level. A model explaining the formation of donor and acceptor centers in Cu-doped and Cd-doped samples is presented.
Electrical and Optical Properties of Ag/p-InP/p-InGaAs Schottky Photodiodes
Authors: Takeda Yoshikazu , Takigawa Shin-ichi , Sasaki Akio
Published: November 2005

Ag/p-InP/p-InGaAs Schottky photodiodes were fabricated with the aim of expanding the spectral response of Ag/p-InP Schottky diodes in the violet and visible region to the infrared region, by adding a p-InGaAs layer to form a heterostructure. The p-InP/p-InGaAs heterostructure was formed by LPE growth and selective etching from a p-InGaAs/p-InP/InGaAsP/InP multiple-layer heterostrucure. A high barrier-height(∼0.8 eV) Schottky contact on the Ag/p-InP gave the heterostructure diodes a low reverse leakage current at room temperature. The diodes are shown to have a very wide spectral response, from 0.4 µm to 1.65 µm, with a fairly flat responsivity and a response-time of 0.5 µs when their diameter is 0.4 mm.
Three-Dimensional Monte Carlo Simulation of Fusion Particle Transport and Its Imaging in Inertial Confinement Fusion
Authors: Mochizuki Takayasu , Katayama Kazuhiko , Fujiwara Etsuo , Sakabe Shuji
Published: November 2005

A three-dimensional Monte Carlo simulation code is developed to describe the transport of fusion-produced particles in inertially-confined fusion plasmas. Simulation results on the energy distribution, spatial image and secondary activation reaction are obtained. The results show that limitations exist to diagnostic approaches such as particle imaging, and thus unfolding procedures such as Monte Carlo simulation are required.
Horizontal Plasma Position Control System for a Tokamak Using Modern Optimal Control Theory
Authors: Ohshima Shigeki , Takamura Shuichi , Okuda Takayoshi
Published: November 2005

A feedback system based on the modern optimal control theory for the horizontal position control of a tokamak plasma device is constructed with an analog sample and hold technique. The efficacy of this system is studied experimentally. High-speed control is realized by analog circuits. The sample and hold method is suitable for separating first-order values from zeroth-order ones, and hence it is useful for the linearization of the non-linear system for a tokamak circuit. These techniques give the guidance for the optimal regulator to control the plasma position.
Transmission Electron Microscope Study of Defects in Cd-Diffused n-InP Substrates
Authors: Ueda Osamu , Ishikawa Hiroshi , Umebu Itsuo
Published: November 2005

Various crystal defects induced in Cd-diffused n-InP substrates have been investigated by transimission electron microscopy. Two types of defects, bulk defects and surface defects, were observed. The former type of defect consists of microdefects uniformly distributed in the diffused area. They are non-strucrural and 100–1000 Å in diameter. These defects are generated in both the diffused regions with and without control of the phosphor pressure. The latter type of defect consists of precipitate-like defects accompanied by dislocation tangles and dislocation networks. These are locally generated and are expected to be eliminated by improving the chemical treatment before diffusion.
Magneto-Optical Effect and Effective Dielectric Tensor in Composite Material Containing Magnetic Fine Particles or Thin Layers
Authors: Abe Masanori , Gomi Manabu
Published: November 2005

We have derived the effective dielectric tensor, including the off-diagonal elements, for a composite material with a structure much smaller than the wavelength of visible light. The boundary problem of the potential has been solved for the electric field induced in a magnetic ellipsoid exposed to a uniform external electric field. The result has been extended to yield the effective dielectric tensor for a composite material containing magnetic fine particles or thin layers dispersed in a nonmagnetic matrix. The component materials may be dielectric or conducting. Using the effective tensor, we have described the light-wave propagation and the magneto-optical effect, together with the light absorption, in the composite material. The criterion for applying the effective tensor is discussed.
Effects of Corona Discharge on the Formation of Electrically-Extracted Liquid Jets
Authors: Kuroda Seiji , Horiuchi Toshio
Published: November 2005

Liquid jets can be extracted from drops when a strong electric field provokes surface instability. The influence of corona discharge from liquid surfaces in air on the dynamic process of jet formation is studied experimentally. A drop of distilled water or KCl aqueous solution is situated at a high voltage metal needle tip and its motion is photographed, with the associated current change being recorded simultaneously. The liquid conductivity ranges from 2.5×10-4 to 2.5 Sm-1. Steady jet emission is observed only when positive voltages are applied, and the manner of emission depends strongly on the conductivity of the liquid. The polarization force and the corona space charge are identified as the most significant factors affecting jet formation. Some characteristics of jet formation, such as jet radii and jet deformation with associated current change, are discussed in conjunction with these factors.
Electrical Properties of High-Molecular-Weight Poly-p-Phenylene Sulfide Films. I. Photoconduction
Authors: Takai Yoshiaki , Inoue Masumi , Shibata Akiji , Mizutani Teruyoshi , Ieda Masayuki
Published: November 2005

The electrical properties of pristine high-molecular-weight poly-p-phenylene sulfide (PPS) films were investigated. The dark current and photocurrent showed a quadratic dependence on the applied field and were inversely proportional to the film thickness at constant field. The photocurrent increased linearly with the light intensity and saturated at higher intensities. These characteristics are explained by the modified space-charge-limited-current model. Preliminary experiments were also carried out on the electrical breakdown of the films.
Absorption Bands of Electrochemically-Colored Films of WO3, MoO3 and MocW1-cO3
Authors: Hiruta Yoichi , Kitao Michihiko , Yamada Shoji
Published: November 2005

Optical absorption bands of electrochemically-colored films of amorphous WO3, MoO3 and Mo
c
W1-c
O3 were investigated. The peak photon energy of the bands depends not only on the amount of injected charges but also on the Mo content. In the WO3 films, the absorption band originates from the intervalence trasfer of electrons. In MoO3 and mixed films, however, the absorption bands are considered to consist of two different components. The first is the intervalence trasfer band and the second is a component of absorption at higher energies. The second component is considered to be related to Mo atoms. The area under the absorption curve increases linearly with increasing density of injected charges in the WO3 film. In the film with large c, the absorption tends to saturate.
Production of Atomic-Oxygen Negative-Ion Beam by Positive Ion-Induced Sputtering of Semiconductive BaTiO3 Ceramic
Authors: Ohya Kaoru , Ishida Keiji , Mori Ichiro
Published: November 2005

When a semiconductive BaTiO3 ceramic surface is bombarded by a keV positive-ion beam, atomic-oxygen negative ions are emitted from the surface in number several tens of times greater than the numbers of other negative ions and neutrals. The dependence of the number of oxygen negative ions on the angle of incidence, the energy and the mass of the bombarding positive ions was investigated, and the ion yield was estimated to be several times greater than 0.1 for the typical conditions. The significance of this finding on techniques for producting negative ions is discussed.
Investigations of Beams Emittance of a Hollow Cathode Ion Source
Authors: Saad Hussein M. , Holk Ole
Published: November 2005

In this article the two-dimensional emittance and brightness for the maximum ion beam current of a hollow cathode ion source is measured. The determination of beam emittance at various source parameters is reported. It is shown that for 50% of the beam at 15 keV the emittance is about 8 mm. mrad. MeV½, while more than 70% of the particle' density is included.
Dispersion Relation of Drift-Wave Instability in a Collisionless Plasma with Sheared Magnetic Field
Authors: Komori Akio , Sato Noriyoshi
Published: November 2005

Detailed measurements are performed on drift-wave instability in a collisionless plasma column under a sheared magnetic field. The instability is found to be destabilized by the small magnetic shear and has a maximum amplitude at the shear length, where the electron thermal speed is nearly equal to the axial phase velocity (controlled by the shear) of the instability. The dispersion relation of the instability agrees with the local theory, which yields almost the same results as the non-local theory taking into account the measured radial density profile of a slender plasma column.
Electrostatic Compensation Method for a Magnetic Field Effect on an Accelerating Lens of a Heavy Ion Beam Source
Authors: Sakai Yoshiyuki , Katsumata Itsuo , Oshio Takanori
Published: November 2005

A method is presented where a heavy ion beam source is used in a strong magneic field (several kG) as the beam source of an ion beam probe for magnetically confined plasmas. A compensating electric field for the magnetic force is applied at the central electrode of the lens of three-electrode type. The broadening of the beam profile and the reduction of the beam current observed in the presence of the magnetic field are compensated for almost to the same value as that in the non-magnetic field case, found by testing in a 1.1 kG-magnetic field using a low energy Cs+ ion beam of 150 eV.
Dielectric Properties of Cholesteryl 2, 2, 3, 3-Tetrafluoropropionate under Hydrostatic Pressure
Authors: Yasuda Naohiko , Fujimoto Sanji , Kawamura Akira , Yano Shinichi
Published: November 2005

The dielectric properties of cholesteryl 2, 2, 3, 3-tetrafluoropropionate were measured under hydrostatic pressures of up to 5 kbar. The reciprocal permittivity ε
-1 was found to vary almost linearly with temperature T in the normal phase I under a pressure p, and the peak value of ε at the I-II (normal-incommensurate) phase transition temperature T
I-II increased with increasing p in the low-pressure region below 3 kbar and tended to saturate in the high-pressure region above 3 kbar. The slope of T
I-II against p was 6°C/kbar in the low-pressure region and decreased in the high-pressure region. The dielectric relaxation curves in phase II shifted towards higher temperatures with p, while the relaxation frequency decreased with p at constant temperature. The relaxation curves converged at the II-III (incommensurate-incommensurate) phase transition temperature T
II-III with decreasing frequency under pressure. The pressure dependence of activation parameters such as the enthalpy, entropy and volume was also estimated. The slope of T
II-III against p was 1.6°C/kbar in the low-pressure region and increased in the high-pressure region. The region of phase II was found to be extended in the low-pressure region and narrowed in the high-pressure region by the application of pressure.
Characteristics of Nb Thin-Film Point-Contact Josephson Junctions
Authors: Naito Seiichi , Higashino Yasushi
Published: November 2005

This paper describes some niobium thin-film point-contact Josephson junctions fabricated by magnetron sputtering and electron-beam lithography. The microwave-inducedI-Vstep characteristics of a junction was expanded at a level of 1.9 mV, showing a step flatness of better than 1 ppm (2 nV) over a current span of 70 µA–the first time such flatness has been observed in thin-film weak links. The junctions are stable and withstand thermal cycling. The distribution of the critical current (Ic) and normal resistance (Rn) at 4.2 K is reported for 32 samples. The temperature dependence of theIcRnproduct was found to agree with the recent Kulik-Omelyanchuk theory of weak links, but some samples hadIcRnproducts greater than those predicted by weak link theories.
A Simple Technique for Obtaining a Stable Frequency Sweep in a Waveguide CO2 Laser
Authors: Kunikane Tatsuro , Ohtsu Motoichi , Nakamura Takuo , Tako Toshiharu
Published: November 2005

A simple technique for obtaining a stable frequency sweep in a waveguide-type CO2 laser is described. The laser was compact, and contained a Stark cell inside its cavity, and the Stark spectrum in NH2D was observed in the frequency range at the 10.6 µm P(20) laser transition. The frequency of the laser was stabilized at the center of the inverted Lamb dip in one of the Stark components, and a stability as high as 2.1×10-11 was obtained at an integration time τ of 250 s. The stabilized laser frequency was swept by slowly varying the d.c. electric field applied to the NH2D molecules. It was swept for the whole frequency range of the single longitudinal-mode oscillation (195 MHz) while maintaining a traceability to the center frequency of the inverted Lamb dip of as high as 5.5×10-10·τ-1/2 for 1 s≦τ≦100 s.
Defect Photoluminescence in Quenched High-Purity Silicon
Authors: Nakashima Kenshiro
Published: November 2005

The quenching of high-purity p-type silicon result in the introduction of several emission lines, at 0.98 eV, 0.92 eV, 0.86 eV, and 0.81 eV, which correlate well with those formerly observed in deformed silicon. These quenched-in emission lines are thermally unstable, in contrast to those in deformed silicon, and vanish on annealing below 200°C. The dislocation density and acceptor concentrations in as-grown samples have no influence on either the formation or the annihilation of the defect responsible for the emission line at 0.98 eV. The activation energy for the annealing of this center is estimated to be about 0.5 eV. It is indicated that none of the emission lines are due to impurity contaminations, but that all are due to quenched-in defects produced during the quenching process. It is suggested that a point defect and/or defect clusters captured in the dislocation core are responsible for the emission line at 0.98 eV.
The Temperature-Dependent Diffusion Mechanism of Zn in InP Using the Semiclosed Diffusion Method
Authors: Kazmierski K. , Huber A. M. , Morillot G. , Cremoux B. de
Published: November 2005

A novel semiclosed diffusion technique for III-V semiconductors has been developed giving ease of control of the operating and junction depth. The secondary-ion mass-spectrometry atom profiles and carrier-concentration profiles have been used to develop a mechanism involving the temperature dependence of neutral Zn formation. Doubly-ionized interstitials are thought to be the diffusion species.
Selenium Thin Film Transistor
Authors: Ogino Toshio , Takeda Akitsu , Mizushima Yoshihiko , Oka Masayoshi , Ito Hideo
Published: November 2005

A new type of thin film transistor utilizing a polycrystalline Se film has been developed. An organic photoresist film is used as the gate insulating layer. The source and drain contacts have a CdSe/Au/SnO2 structure. In this device, maximum temperature in the fabrication process is as low as 210°C, and the entire deposition process is performed by vacuum evaporations. The device exhibits enhancement-type characteristics. When V
D=-20 V and V
G=-20 V, the on-off ratio is more than 103 and drain current about 1 µA. An enhancement/depletion type inverter is fabricated by using a device with Te/Au/SnO2 electrodes as a depletion-type element. The current drift is discussed in terms of carrier trapping in the insulating layer.
Red Electroluminescence and Crystallinity of ZnS:SmF3 Thin Films
Authors: Ohwaki Junichi , Tsujiyama Bunjiro , Kozawaguchi Haruki
Published: November 2005

The dependence of the red emission characteristics (emission efficiency, brightness and emission decay time) and crystallinity of ZnS:SmF3 thin-film electroluminescent (TFEL) devices upon fabrication parameters such as the SmF3 concentration and substrate temperature during evaporation, has been investigated. The electroluminescent characteristics are considered to be influenced more by the SmF3 concentration and the grain height in the film thickness direction, than by the cubic ZnS structure {111} plane orientation and the film uniformity, or by the degree to which the cubic {111} plane is oriented parallel to the substrate. A bright red electroluminescence of 1000 cd/m2 under 5 kHz sinusoidal voltage excitation and an emission efficiency of 0.078 lm/W are obtained in these ZnS:SmF3 TFEL devices.
Anomalous Discharging Current Peak in Unstretched α-Form Polyvinylidene Fluoride
Authors: Yamada Tatsuro , Mizutani Teruyoshi , Ieda Masayuki
Published: November 2005

The discharging current in α-form polyvinylidene fluoride (PVDF) showed an anomalous peak at high temperatures above 100°C. An increase in the charging field E
c or the charging time t
c reduced the peak current J
p and increased the time required to reach J
p. The amount of released charge Q
r associated with J
p, however, remained almost constant with increasing E
c or t
c. Q
r was much larger than the maximum value (\doteqdot
ε
r
ε
0
E
c) of the space charge existing in the specimen. The anomalous discharging current peak was not observed in a PVDF/PP specimen with a thin blocking PP (polypropylene) film, regardless of the polarity of E
c. Hole injection from the anode and neutralization of positive ionic species at the cathode are indicated as playing an important role in producing the anomalous peak.
Formation of Pyroelectricity in Unoriented Polytrifluoroethylene
Authors: Oka Yoshio , Koizumi Naokazu
Published: November 2005

Pyroelectricity in polytrifluoroethylene was studied in detail on unoriented samples. The pyroelectricity was found to be anomalous as regards the temperature dependence of the pyroelectric coefficient, since the latter changed signs twice over the temperature range 100 to 350 K. Also, the sample with the lowest initial crystallinity exhibited the greatest degree of pyroelectric activity. Crystallization coupled with poling was found to be responsible for the pyroelectricity, i.e., spontaneous polarization was induced in the new crystalline region developed during the poling process, and not in the existing crystalline region, because it is difficult for the main chain in the crystal to rotate. The spontaneous polarization was found to increase as the temperature was increased from 185 to 273 K, resulting in the anomalous pyroelectricity. A model analogous to ferrielectricity is proposed to explain this phenomenon.
Derivation of the Spectral Width of a 0.8µm AlGaAs Laser Considering 1/f Noise
Authors: Ohtsu Motoichi , Kotajima Shinichi
Published: November 2005

The spectral profile of a CSP-type 0.8 µm AlGaAs laser and its spectral width (FWHM) were estimated from experimental results on the lasers FM noise at room temperature. The power-independent spectral width was also derived from the recently-reported power-independent 1/f noise. The result was 2.0 MHz, which agrees well with previous experimental results. The power-dependent width Δν was also derived as 2.0 MHz<Δν≦8.8 MHz for 0<(I/I
th-1)-1≦7, where I and I
th represent the injection current and its threshold value, respectively.
Subsolidus Phase Study of MO–Nd2O3–WO3 (M=Ca, Sr, Ba, Mg and Zn) and Nd2O3–GeO2–WO3 Systems
Authors: Yasuda Gōichi , Sato Hidetaka , Ikeda Takuro
Published: November 2005

Subsoildus phase equilibria have been investigated in six ternary systems, CaO–, SrO–, BaO–, MgO– and ZnO –Nd2O3–WO3 and Nd2O3–GeO2–WO3. Twelve ternary compounds and five solid solutions were found to exist in the respective systems. Fluorescent activity was detected for powdered scheelite-type solid solution specimens in systems including CaO, SrO or GeO2.
Comparison of Nb Thin-Film Point-Contact Josephson Junction Characteristics with the Stewart-McCumber Model
Authors: Naito Seiichi , Higashino Yasushi
Published: November 2005

This paper compares the measured characteristics of a three-dimensional Nb thin-film point-contact junction with those predicted by the Stewart-McCumber model. The erratic microwave-induced I-V characteristic we observed at low microwave power levels was also evident in a digital simulation –based on the Stewart-McCumber model–of the time dependence of the junction voltage and the phase space trajectory.
Subharmonic steps V=(n/m)(h
f/2e) were observed when a 70 GHz signal was applied, but the usual condition ωC
R
n≃1 for substeps was not fulfilled. Substeps were also observed in the digital simulation even when the current-phase relationship was purely sinusoidal.
Lag and Resolution Related with Current Distribution of Electron Beam in Camera Tubes
Authors: Hatanaka Yoshinori , Aoyama Mitsuru
Published: November 2005

The effect of the current distribution across the electron beam on beam discharge lag and resolution capability of camera tubes are investigated analytically and experimentally. It is found that the resolution capability and beam discharge lag are dominated by both the current density distribution, especially at the leading edge, and by the equivalent temperature of the scanning electron beam. Experimental results show that a rectangular beam, cross section with 100 µm (horizontal size)× 40 µm (vertical size) on the target, can resolve more than 800 TV lines in standard scanning format fat a 1 inch diameter tube (1/2'' wide×3/8'' high) and also reduce beam discharge lag, for example to about 30% compared with that for a narrow beam at the same beam temperature.
Studies on Dielectric Properties of Binary Polar Mixtures of n-Butanol-Mutual Correlation and Excess Thermodynamic Functions
Authors: Swain B. B.
Published: November 2005

Dielectric constant of binary mixtures of six polar liquids with n-butanol has been measured at radio frequency. The data has been utilised for calculation of (i) mutual correlation factor, g
ab, between the unlike molecules and (ii) contribution of the unlike molecules to the excess free energy of mixing, Δ
F
ab, and excess entropy Δ
S
ab. The value of g
ab in mixture of the alcohols (n-butanol with methanol and n-propanol) remains above unity while for mixtures where the other component is a nonassociated liquid (n-butanol in chlorobenzene/aniline/ethyl benzoate/methyl benzoate) go below unity. These indicate predominance of microheterogeneous clustres with co-operative angular correlation (α-cluster) in the case of alcohol mixtures and of clusters with destructive angular correlation (β-cluster) in mixtures where one component is a non-associated liquid. The excess thermodynamic parameters calculated from this data also qualitatively support this view.
Vapor-Phase Epitaxial Growth of GaAs by the Single Flat Temperature Zone Method
Authors: Koukitu Akinori , Kouno Satoshi , Takashima Kouichirou , Seki Hisashi
Published: November 2005

The VPE growth of GaAs using the single flat temperature zone (SFT) method with the GaAs (crust)–AsCl3–He–H2 system is described. The growth in this system is kinetically limited and occurs selectively on the substrate. High-purity GaAs is obtained in the low AsCl3 mole fraction range, and the AsCl3 mole fraction effect is not observed in this system as it is in other SFT systems. It is concluded that the present system is the most promising of the four SFT systems.
Growth Rate of Polyethylene Single Crystals at High Pressure
Authors: Hikosaka Masamichi , Seto Tsuneo
Published: November 2005

The growth kinetics of extended-chain single crystals (ECSC) of polyethylene are studied. The results of an expertment on the growth rate and the structure of the high-pressure form suggest that the segments in the crystal slide along their own axes very easily and that the ends of the segments form uneven contour surfaces so as to minimize the boundary free energy. On such a secondary nucleus model, we assume that the elementary step of the growth is the “creeping in” of a repeating unit linked directly to a crystalline segment through the boundary surface of the nucleus. We have the normal growth rate V∝=Texp
(-G
*/3 k
T), where ΔT is the degree of supercooling and G
* is the least free energy of formation of a critical nucleus. By fitting this relation with the experimental one, we obtain G
*=134/ΔT (kJ/mol) at 300 MPa, a value 1/14 of that at 0.1 MPa.
Optical and Electrical Properties of CuInS2 Thin Films by Spray Pyrolysis
Authors: Onnagawa Hiroyoshi , Miyashita Kazuo
Published: November 2005

The optical, electrical and structural properties of CuInS2 thin films prepared by spray pyrolysis have been studied. The polycrystalline films produced by spraying a solution of Cu (CH3COO)2H2O, InCl3 and (NH2)2CS with the atomic ratio Cu:In:S=1:1:2.8∼1:1:3.2 and annealing at 500°C for 2 hours were nearly stoichiometric, and the depth profiles of the atomic composition were flat except near the surface. The optical band gap at room temperature was 1.43 eV, and the polarity of the thermoelectromotive force showed p-type conduction at a sulfur concentration ratio to Cu[S]≥2.8. The activation energy of conductivity was 0.3 eV.
Chevrel Phase Grain Flocculated Films Linked by Chemical Cross-Linking
Authors: Obara Kozo , Ogushi Tetuya
Published: November 2005

A new method of forming superconducting grain flocculated films is presented. Chevrel phase compounds are used as superconducting grains, and these are combined with organic barriers. The barriers are formed by catalytic reaction on the grain surface, and are useful for Chevrel phase compound Josephson junctions. The grain flocculated film is composed of Josephson coupled grains. The importance of the orthokinetic flocculation and the mechanical syneresis for the flocculation process is shown. The temperature dependence of dV/dI is measured from 300 K to 4.2 K, and the magnetic field dependence of dV/dI is measured up to 1 kG. Below T
c, the I-V curve shows current steps up to n=3, with a voltage interval of approximately 45 mV. These current steps are proof that at least twenty junctions connected in series act coherently.
Quasi-Nondestructive Observation of Oxidation-Induced Stacking Faults in Silicon by Photoacoustic Topography
Authors: Nakamura Hiromichi , Tsubouchi Kazuo , Mikoshiba Nobuo
Published: November 2005

Oxidation-induced stacking faults (OSF) have been observed quasi-nondestructively by photoacoustic topography. Photoacoustic (PA) signals were detected with a ZnO transducer made by sputtering on the back surface of a sample. We found a good correlation between the PA topograph and the distribution of OSF. The spatial resolution was about 60 µm in the present PA topography.
Pulse Power Compression by Fast Opening Switch
Authors: Miyamoto Shuji , Yoshinouchi Atushi , Yugami Noboru , Imasaki Kazuo , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

A Parameter survey for an inductive storage pulse compression system in a vacuum is presented. The plasma erosion switch was considered a fast opening switch. The optimum power amplification and efficiency were obtained with respect to opening start time, input pulse width and load impedance. A switch with faster opening speed was desired for the high preformance of the pulse compression system. An analysis of the plasma erosion switch showed that switch plasma which has a low density, small area and a high injection velocity is required for the pulse compression system.
Effects of Growth Conditions on Electron Trap Concentrations in Si-Doped Al0.2Ga0.8As Grown by MBE
Authors: Naritsuka Shigeya , Yamanaka Kenichi , Mihara Minoru , Ishii Makoto
Published: November 2005

Electron traps in Al0.2Ga0.8As layers grown by molecular beam epitaxy were investigated with DLTS. Six electron trap levels were observed. The dominant level (ME6) has a thermal activation energy of 0.71 eV, and its concentration decreases with increasing growth temperature and decreasing group V/III beam flux ratio. It is suggested that ME6 is related to a Ga vacancy or a Ga vacancy complex.
Effects of Substrate Temperatures and V/III Ratios on Epitaxial InP Grown by Metalorganic Chemical Vapor Deposition
Authors: Uwai Kunihiko , Susa Nobuhiko , Mikami Osamu , Fukui Takashi
Published: November 2005

InP epitaxial layers are grown on InP(100) substrates by low-pressure metalorganic chemical vapor deposition (MOCVD) without a PH3 pyrolysis oven. Growth rates increase from 1.8 µm/h to 2.4 µm/h and the epitaxial layer quality is improved when the substrate temperatures are increased from 550°C to 650°C. When the molar ratio [PH3]/[TEI] in the vapor is varied between 65 to 325, no significant changes in carrier concentrations and mobilities for epitaxial layers are observed. InP epitaxial layers grown by MOCVD do not show p/n conversion.
Plasma-Enhanced Chemical Vapor Deposition of Fluorinated Silicon Nitride
Authors: Fujita Shizuo , Toyoshima Hideo , Ohishi Toshiyuki , Sasaki Akio
Published: November 2005

Fluorinated silicon nitride films are deposited by the plasma-reaction of SiF4–N2–H2 gas mixture. The fluorine content in the film is ∼25 at%. Although hydrogen is incorporated in the form of N–H bonds, the bondings remain stable up to 640°C. The films have relatively high resistivity (7×1016 Ωcm at 2 MV/cm), high breakdown strength (10 MV/cm), and low deep trap density.
Chemical State Depth Profile for GaAs Surface
Authors: Kohiki Shigemi , Oki Kazue , Ohmura Takuichi , Tsujii Hiraaki , Onuma Takeshi
Published: November 2005

Angular dependent core-level X-ray photoelectron spectra measurement has been performed for native oxide of single crystal GaAs wafer and proved to be a useful method for obtaining chemical state depth profile near the surface. Metallic arsenic is buried in a growing native oxide layer and stranded at the interface layer of oxide and GaAs substrate.
Evaluation of the Integrated Emissivity of a Black Body
Authors: Ohwada Yoshiko
Published: November 2005

The integrated emissivity of isothermal diffuse cavities is evaluated for various distances of the detector from the cavity. Uncertainty in the computed value of the integral emissivity is larger for a smaller distance for a given cavity.
Bi-Level Structures for Focused Ion Beam Using Maskless Ion Etching
Authors: Matsui Shinji , Mori Katsumi , Shiokawa Takao , Toyoda Koichi , Namba Susumu
Published: November 2005

This paper proposes a bi-level structure for a maskless ion etching using focused ion beam. The bi-level structure can be realized by using a new phenomenon, wherein the Ga+ doped AZ1450J bottom layer is etched off by a high dose of more than 0.76 µC/cm. A Si top layer with 70 nm linewidth is fabricated. The linewidth can be controlled to nanometer dimensions by changing the dose. Moreover, fine structures with 100 nm are demonstrated using bi-level structures for the substrate etching and lift-off processes.
Optical and Electrical Properties of Electrochemically Doped n- and p-Type Polythiophenes
Authors: Kaneto Keiichi , Ura Shogo , Yoshino Katsumi , Inuishi Yoshio
Published: November 2005

Absorption spectra have been measured on polythiophene films subjected to electrochemical Bu4N+ doping. The spectra show essentially the same evolution as those for BF-
4 doping, i.e., peaks at 0.6∼0.7 eV and 1.5∼1.8 eV appear upon doping in addition to the band-to-band absorption peak at 2.6 eV. Propagation velocities of electrochemical doping of Bu4N+ and BF-
4 along polythiophene films were estimated to be on the order of 10-3 cm/sec.
Substrate-Induced Stabilization of GaInPAs Epitaxial Layers on GaAs and InP
Authors: Ishikawa Masayuki , Ito Ryoichi
Published: November 2005

The unstable regions of mixing have been calculated directly for III-V quaternary GaInPAs alloy layers epitaxially grown on GaAs and InP substrates. The lattice mismatch strain energy due to the existence of the substrate has been included in the free energy of the epitaxial material. The result shows that the quaternary GaInPAs epitaxial layers, once grown on GaAs and InP, are stabilized by the existence of the substrates even at low temperatures and the decomposition into two phases may not occur.
A Practical Method of Preparing Thin Homogeneous Ferroelectric Smectic Cells for Electro-Optical Microsecond Switches (II): Sm A Liquid Crystal Growth under a Temperature Gradient
Authors: Ishikawa Ken , Hashimoto Kenji , Takezoe Hideo , Fukuda Atsuo , Kuze Eiichi
Published: November 2005

A large size homogeneous monodomain cell is prepared by growing smectic A under a temperature gradient. The nucleation of aligned smectic A is initiated with the aid of a spacer edge. The temperature gradient is obtained by using an ITO electrode properly etched as a local heater. The obtained monodomain size is at least one square millimeter.
Parallel Conduction Correction to Measured Room Temperature Mobility in (Al, Ga)As–GaAs Modulation Doped Layers
Authors: Lee K. , Shur M. S. , Klem J. , Drummond T. J. , Morkoç H.
Published: November 2005

We describe a set of measurements which allows for correction of the measured room temperature two dimensional (2-D) electron gas Hall mobility in (Al, Ga)As–GaAs modulation doped structures to account for parallel conduction effects in the doped (Al, Ga)As layer. The measurements confirm that the actual values of the 2-D electron gas mobility are very close to 9200 cm2/Vs for samples with a variety of apparent Hall mobilities and undoped spacer layer thicknesses. This demonstrates that the room temperature mobility is nearly independent of the 2-D electron gas concentration n

s
when n

s
<1012 cm-2.
30 nm Line Fabrication on PMMA Resist by Fine Focused Be Ion Beam
Authors: Shiokawa Takao , Aoyagi Yoshinobu , Kim Pil Hyon , Toyoda Koichi , Namba Susumu
Published: November 2005

A 30 nm line pattern with 0.4 µm depth was successfully fabricated on a PMMA resist by a 100 kV focused Be++ beam emitted from Au–Si–Be ternary alloy ion source. The line width fabricated decreased with the decrease in ion dose.
XPS Study on Oxide/GaSb Interfacial Chemical Reaction at Room Temperature
Authors: Mizokawa Yusuke , Komoda Osamu , Iwasaki Hiroshi , Nakamura Shogo
Published: November 2005

The room temperature oxidation of GaSb in air has been monitored for 3 years by XPS. The depth profiles of the 3 years-grown oxide clearly show that the over layer composition changed for a prolonged length of time; the amount of Sb2O3 decreased whereas those of Ga2O3 and elemental-Sb increased. The results show that the interfacial reaction of 2GaSb+Sb2O3→Ga2O3+4Sb proceeded gradually even if the sample was kept at room temperature.
Plasma-Deposited Silicon Nitride Films from SiF2 as Silicon Source
Authors: Fujita Shizuo , Toyoshima Hideo , Ohishi Toshiyuki , Sasaki Akio
Published: November 2005

SiF2 gas is used instead of SiF4 as a reactant source for the plasma-deposition of silicon nitride. As compared with the reaction from the SiF4–N2–H2 gas mixture, (i) the deposition rate is higher at the same N/Si ratio, (ii) more nitrogen, less fluorine and less oxygen are incorporated in the film, and (iii) the film can be deposited without H2 gas. These results can be attributed to higher reactivity of the SiF2 gas.
Time-Resolved Measurement of Electron Density in Atmospheric Kr–F2–He Discharge by the Streak Interferometric Method
Authors: Tachikawa Jin , Maekawa Kazuhiro , Takubo Yoshitaka
Published: November 2005

Using the streak interferometric method, we have made time-resolved electron density measurements on Kr–F2–He mixtures excited by a short pulsed electric discharge in the pressure range appropriate for rare-gas-halides lasers. The observed rise and decay are found to be determined mainly by ionization of Kr atoms and electron attachment by F2 molecules, respectively. The rate for the latter process is obtained from a comparison of the experiment with the simulation calculation.
Improved Threshold Voltage Uniformity in GaAs MESFET Using High Purity MOCVD-Grown Buffer Layer as a Substrate for Ion Implantation
Authors: Sano Yoshiaki , Nakamura Hiroshi , Akiyama Masahiro , Egawa Takashi , Ishida Toshimasa , Kaminishi Katsuzo
Published: November 2005

High purity and high resistivity MOCVD-grown GaAs layer was found to be a very suitable substrate for the fabrication of MESFET by direct ion implantation. Such a substrate (MO-substrate) has been grown using a low pressure MOCVD system by adjusting the [AsH3]/[TMG] ratio. MESFET's were fabricated using a W–Al gate self-alignment process, and V
th scattering was compared between the MO-substrate and an undoped LEC substrate. Extremely small V
th standard deviation of 18.5 mV was obtained in a 2-inch full wafer of MO-substrate at a mean value of +220 mV.
TEM Observations of the Grain Boundaries in a Semiconducting Barium Titanate Thick Film
Authors: Koumoto Kunihito , Tagawa Hiroshi , Nakano Tadashi , Takeda Shunji , Yanagida Hiroaki
Published: November 2005

Transmission electron microscope observations of the grain boundary areas were made on semiconducting barium titanate thick film which had shown a typical PTC (positive temperature coefficient of resistivity) effect. The 180° domains across the grain boundary could not be observed, while the possibility of the existence of 90° domains was suggested. The fact that intergranular phases were unobservable indicated no significant role of the second phase in a basic PTC effect.
New Dynamic Image Processing Technique for the Analysis of Texture Movement: Study of the Dissipative Structure in the Electrohydrodynamic Instability of Nematic Liquid Crystal
Authors: Miike Hidetoshi , Ikemoto Syunichi , Ochiai Kouji , Hashimoto Hajime , Ebina Yoshio
Published: November 2005

A dynamic texture image processing technique is developed. A moving texture is sampled every 0.42 s and a time series of 128 dynamic frames is obtained. Each frame is constructured by 32×32 pixcels with 64 gray scale levels of brightness. From the time course of each pixcel's brightness, a correlation time and a variance are calculated; then a “correlation image” and “variance image” of the moving texture are constructed. This technique is applied to the analysis of dissipative structures in the electrohydrodynamic instability of nematic liquid crystal. Interesting information about dynamic behavior is obtained.
New Electro-Optic Effect of Microsecond Response Utilizing Transient Light Scattering in Ferroelectric Liquid Crystal
Authors: Yoshino Katsumi , Ozaki Masanori
Published: November 2005

A new type of display device (transient scattering mode device) utilizing transient light scattering in ferroelectric liquid crystal accompanied by domain switching by field application is proposed and shows excellent characteristics. The switching time is in the µs range and is shorter in material with larger spontaneous polarization and at higher fields. The contrast is also extremely high compared with other devices. The optical polarizer and special technique for the molecular alignment are not necessary in this device.
Small Area Planar Nb/Nb Josephson Tunnel Junction with High Current Density
Authors: Takayanagi Hideaki , Kawakami Tsuyoshi
Published: November 2005

Small area planar Nb/Nb tunnel junctions with high current density have been fabricated using electron-beam lithography and selective anodic oxidation method. The anodic Nb oxide film worked well as an insulator between the upper and bottom Nb electrodes. The junction area was as mall as from 1.3 to 2.0×10-9 cm2 and the junction showed a critical supercurrent density of from 105 to 106 A/cm2. I-V characteristics showed that the junction was composed of a double normal/super proximity sandwich. It was found that junction characteristics depended strongly on those for the top normal layer, formed at the top Nb electrode deposition on the tunnel oxide.
Actively Mode-Locked and Q-Switched Phosphate Glass Oscillator
Authors: Tomie Toshihisa , Kasai Takeshi , Yano Masaaki
Published: November 2005

An actively mode-locked and Q-switched phosphate glass oscillator is studied. Observed pulse widths agree quite well with the active mode-locking theory. Stable and reproducible pulses of 100 ps to 2 ns are obtained. The pulses can be synchronized to external events with the precision of less than 30 ps. The single pulse energy is around 150 µJ. The stabilities of pulse width and pulse energy are 3% The oscillator operates at up to 4 Hz repetition rate.
LPE Growth of GaInAsP on (100)GaAs by a Two-Phase-Solution Technique
Authors: Kawanishi Hideo , Suzuki Takeshi
Published: November 2005

LPE growth condition and characteristic of GaInAsP lattice matched with (100)GaAs by a two-phase-solution growth technique is reported. This technique is applied to the LPE growth at T
g=840°C and high quality Ga0.55In0.45As0.07P0.93 is obtained.
Electron Cyclotron Resonance Plasma Deposition Technique Using Raw Material Supply by Sputtering
Authors: Ono Toshiro , Takahashi Chiharu , Matsuo Seitaro
Published: November 2005

A low temperature plasma deposition method using a raw material supply by sputtering has been developed. A microwave electron cyclotron resonance technique was used for highly ionized plasma generation and plasma stream extraction at low gas pressures of 10-3 to 10-1 Pa. Gas molecules, and particles sputtered by ions in the plasma stream are ionized and transported to the specimen substrate with an energy of 10 to 30 eV. Fully oxidized, dense and high quality films of tantalum oxide and aluminum oxide were obtained at room temperature.
Submicron Channel MOSFET Using Focused Boron Ion Beam Implantation into Silicon
Authors: Shukuri Shoji , Wada Yasuo , Masuda Hiroo , Ishitani Tohru , Tamura Masao
Published: November 2005

A new submicron channel length device, ion beam MOSFET (IB-MOS), is proposed as an effective application of focused-ion-beam implantation into silicon. The effective channel region of this device is formed by the one line scan of a 16 keV, focused B+ ion beam (diameter: 0.2 µm, current density: 50 mA/cm2) in an As+ implanted n- gate region between the source and drain. It is demonstrated by two dimensional device simulation that significant improvements in current gain, drain breakdown voltage and short-channel threshold effect are achieved for IB-MOS devices with 0.8 µm source-drain spacing. A fabricated IB-MOS device verifies the results of the simulation, except for the current gain, because of the high impurity effect in the channel region, which could be improved by choosing appropriate channel implantation conditions.
Carrier Mobility in Poly-p-Phenylenesulfide
Authors: Yoshino Katsumi , Yun Mun Soo , Ozaki Masanori , Inuishi Yoshio
Published: November 2005

Carrier mobility of poly-p-phenylenesulfide (PPS) is studied by the time of flight method. The polarity effect of induced charge indicates that the hole is predominant carrier in PPS. The mobility of hole in PPS at room temperature is evaluated as 4×10-4 cm2/V.sec. It increases at higher temperatures with an activation energy of about 0.2 eV.
GaAs Radical Etching with a Cl2 Plasma in a Reactive Ion Beam Etching System
Authors: Sugata Sumio , Asakawa Kiyoshi
Published: November 2005

GaAs radical etching, similar to that reported with a Br2 plasma in a reactive ion etching system, has been confirmed in a Cl2 gas reactive ion beam etching system for the first time. Ion bombardment was completely suppressed with a sample faced opposite to the ion source. Etching rates at substrate temperatures of 300 to 400°C were 30 Å/min to 10µm/min. The etched surface was very smooth and showed crystallographic orientation to expose the {111}A facet. Apparent activation energy was about 500 kcal/mol. It is expected that a damage- and contamination-free surface can be obtained by this radical etching technique.
Evidence for Quantum Diffusion of Hydrogen in Ta: Quench-Recovery Experiments Revisited
Authors: Fukai Yuh
Published: November 2005

The diffusion coefficient over wide temperature ranges was obtained for the first time on H, D, and T in Ta from a re-analysis of quench-recovery experiments. The results provide clear evidence of quantum tunneling at low temperatures (\lesssim100 K).
Phase-Locked Epitaxy Using RHEED Intensity Oscillation
Authors: Sakamoto Tsunenori , Funabashi Hideo , Ohta Kimihiro , Nakagawa Tadashi , Kawai Naoyuki J. , Kojima Takeshi
Published: November 2005

Long lasting RHEED oscillations during MBE growth of GaAs and Al
x
Ga1-x
As are observed. Using these oscillations, accurate measurements of GaAs, Al
x
Ga1-x
As growth rates and the Al mole fraction x were performed during the growths. The phase of the RHEED oscillations was analyzed by computer and molecular beam shutters were operated at a particular phase. This computer controlled phase-locked epitaxy (PLE) was applied to grow precisely defined (GaAs)2(AlAs)2 bi-layer superlattices. Raman scattering spectra showed split lines characteristic of superlattices. This PLE method is invulnerable to molecular beam fluctuations.