bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Trapping Parameters from TSC in Polyethylene
Authors: Mizutani Teruyoshi , Suzuoki Yasuo , Hanai Masahiro , Ieda Masayuki
Published: November 2005

The trapping parameters of one of the carrier traps in low-density polyethylene were evaluated by using the X-ray-induced thermally-stimulated current (TSC) technique. The values obtained were E
t (trap depth): 0.90 eV, µτ (product of mobility and lifetime): 5×10-13 m2/V and n
to (initial density of trapped carriers): 2.9×1020 m-3. Assuming the fast retrapping case, N
t (trap density) was 1.4×1021 m-3 and, assuming the slow retrapping case, S
t (capture cross-section) and ν (attempt-to-escape frequency) were 1.1×10-17 m2 and 3×1013 sec-1, respectively. Whether the retrapping was fast or slow, was not determined from the TSC results only.
Target Erosion Pattern in Planar Magnetron Sputtering
Authors: Fukami Tatsuo , Sakuma Toshiyuki
Published: November 2005

Two methods for visualizing the target erosion pattern in the planar magnetron sputtering system are described here. The experimental results obtained by one of the new methods reveal that there exists a threshold vertical magnetic field corresponding to the erosion pattern boundaries. The effect of the working pressure and of the cathode potential on the erosion pattern is explained in terms of the mean free path and the initial velocity of the secondary electrons, respectively.
Ellipsometric Studies on Sputter-Damaged Layer in n-InP
Authors: Takahashi Yasuhito , Sakai Shiro , Umeno Masayoshi , Hattori Shuzo
Published: November 2005

Using multiple incident angle ellipsometry, the complex refractive index and the thickness of the damaged layer formed by SiO2 sputtering deposition were determined. An analysis of a least-squares fit of the experimental values Δ

i
and \varPsi
i
to the theoretical results is carried out in three steps, where Δ

i
and \varPsi
i
are the phase change and the azimuth, respectively, at an angle of incidence φ
i
. It is found that a point several hundreds of angstroms from the surface is damaged even though the thickness of the deposited film is only some tens of angstroms. The change in the complex refractive index n
d–jk
d and the thickness t
d of the damaged layer does not depend on the deposition time, but these quantities increase with increasing sputtering power. Typical values for n
d–jk
d and t
d are 3.684–0.389j and 640 Å, respectively at a sputtering power of 300 W.
Composition and Structure of Anodic Oxide Film on Iron in Neutral Phosphate Solution
Authors: Tokunaga Katsushi
Published: November 2005

The composition and structure of anodically-formed iron oxide film in nearly neutral phosphate solution was examined by means of ESCA, electron diffraction and FT-IR spectroscopy. In the active region and in deaerated phosphate solution at pH 6.0 or lower, ferrous phosphate –Fe3(PO4)2·8H2O– was formed. In the presence of air, a small amount of ferric phosphate was found. On the other hand, in the passive region at high pH, for example at pH 9.1, the iron was covered with a multiple oxide film. The structure of the film was found to consist of an inner “Fe3O4” layer and an outer “γ-Fe2O3, FePO4·nH2O or γ-FeOOH” layer, the outermost part of the film containing a small quantity of reaction products or contaminations such as Na+, Ca2+, PO3-
4. The most passive films were estimated to be 30–50 Å.
Ba(Zn1/3Nb2/3)O3–Sr(Zn1/3Nb2/3)O3 Solid Solution Ceramics with Temperature-Stable High Dielectric Constant and Low Microwave Loss
Authors: Onoda Makoto , Kuwata Jun , Kaneta Kumiko , Toyama Keiichiro , Nomura Shoichiro
Published: November 2005

Solid solution ceramics in the Ba(Zn1/3Nb2/3)O3(BZN)–Sr(Zn1/3Nb2/3)O3 (SZN) system have been studied with a view to finding materials for use as dielectric resonators at microwave frequency. The relative dielectric constant and the unloaded Q at 10 GHz are respectively 41 and 5400 for BZN, and 40 and 2000 for SZN. The temperature coefficient of the resonant frequency is estimated as 30 ppm/°C for BZN and -38 ppm/°C for SZN. The dielectric constant of 0.3 BZN–0.7 SZN ceramic is nearly independent of temperature, which gives a very small estimated temperature coefficient of the resonant frequency of -5 ppm/°C.
Measurement of Residual Stress in Bent Silicon Wafers by Means of Photoluminescence
Authors: Yasutake Kiyoshi , Umeno Masataka , Kawabe Hideaki , Nakayama Hiroshi , Nishino Taneo , Hamakawa Yoshihiro
Published: November 2005

The photoluminescence (PL) method was used to measure the residual stress in plastically-bent Si single crystal wafers. The bound-exciton PL line showed remarkable energy shift by the residual stress and the stresses measured from the PL shift agreed well with values of the stress deduced from the theory of plastic bending. It was found that the residual stress introduced by the plastic deformation is quite different in floating-zone (FZ) wafers from that in Czochralski (CZ) Si wafers, possibly because of the difference in the generation and multiplication processes of dislocations in the two crystals. Annealing of the bent specimen at 1000°C reduced the residual stress in the specimen, and the peak position of the bound-exciton PL line reverted to that before bending.
Anomalous Magneto-Optic Kerr Effect in Ordered Perovskites A2FeMoO6 (A=Ba, Sr, Ca)
Authors: Shono Keiji , Abe Masanori , Gomi Manabu , Nomura Shoichiro
Published: November 2005

The polar Kerr rotation and ellipticity, together with the reflectivity, have been measured at λ=0.4-1.5 µm in hot-pressed ceramics. The Kerr rotation forms a very large peak reaching as much as 1 deg at room temperature, and the ellipticity shows a broad dispersion-like anomaly at λ=1-1.1 µm, where the reflectivity exhibits an anomalous characteristic of the plasma edge. The Kerr and reflectivity spectra are markedly changed by oxidizing the sample in air, either at room temperature or at high temperature (400°C). The Mössbauer absorption spectra of Fe57 have revealed that the oxidization due to the heat-treatment is restricted only within the surface layer of the sample.
Observation of Undulator Radiation. I. Operation Studies and Visual Observation
Authors: Kitamura Hideo , Tamamushi Shuichi , Yamakawa Tatsuya , Sato Shigeru , Miyahara Yoshikazu , Isoyama Goro , Nishimura Hiroshi , Mikuni Akira , Asaoka Seiji , Mitani Shichiro , Maezawa Hideki , Suzuki Yoshio , Kanamori Hideto , Sasaki Taizo
Published: November 2005

A 19-pole permanent magnet undulator has been tested by inserting it into a straight section from outside the vacuum chamber of the SOR-RING, a dedicated synchrotron radiation source operated between 0.2 and 0.38 GeV. It was confirmed that the undulator field did not seriously disturb stable operation by observing the shift of the closed orbit and the shift of the betatron numbers. Some results of visual observation of the radiation are presented. The polarization character was studied on the rainbow circle with a polarizer and some theoretical results by Kitamura were confirmed. It was found that the interfering synchrotron radiations along the straight section of the storage ring make a series of rainbows even without the undulator field.
He–Zn+ Ion Laser Using Hollow-Cathode Discharge with High-Voltage Operation
Authors: Iijima Tetsuo
Published: November 2005

To improve the oscillation characteristics of the He–Zn+ ion laser, a new type of high-voltage hollow-cathode discharge (HV-HCD) was employed as an excitation source. The high voltage of this laser tube is obtained by restricting part of the inner cathode wall using insulators. The output power characteristics of the 7588 Å transition in ZnII are compared with those obtained using the conventional coaxial-type HCD laser tube.
In the conventional HCD laser tube, a saturation or a quenching in the laser power has been observed over a wide He pressure and Zn vapor pressure range. However, in the HV-HCD laser tube, these phenomena are not observed over the entire experimental range. Moreover, the slope of the dependence of the discharge current on the laser power is much steeper.
Temperature Dependence of Lasing Characteristics of InGaAsP/InP Distributed Feedback Lasers in 1.5 µm Range
Authors: Akiba Shigeyuki , Utaka Katsuyuki , Sakai Kazuo , Matsushima Yuichi
Published: November 2005

The temperature dependence of the lasing characteristics of InGaAsP/InP distributed feedback injection lasers in the 1.5 µm wavelength range is presented. The threshold current density is expressed phenomenologically using the characteristic temperature T
0 of a Fabry-Perot laser and a spectral gain distribution of Gaussian type, which almost agreed with the experimental results in the temperature range of constant T
0. The temperature coefficient of the lasing wavelength was found to be 1.0 Å/K experimentally and calculations taking into account the effect of carrier density could explain this value well. It was also shown that a TM output also appeared in the low-temperature range even if only TE modes were observed at room temperature and at higher temperatures.
Light Beam Deflection in Polymer Films by Dielectric Loss Heating
Authors: Yamada Takeshi , Kurokawa Takashi
Published: November 2005

Light beam deflection caused by local refractive index change in polymer optical waveguide films was investigated experimentally and theoretically. The local refractive index change was induced by dielectric loss heating with an RF electric voltage applied to the electrodes deposited on the optical waveguide films. The incident light was deflected by the induced refractive index gradient in the film plane. The deflection angle depends on the guide thickness and the film thermal conductivity. The angle was approximately 5 degrees for a 190 µm thick polymethylmethacrylate film. Deflection speed was 150–200 msec. An application to a new 1×3 switch was also proposed and demonstrated.
Brillouin-Backscattering from Plasma Produced by a Long CO2-Laser Pulse
Authors: Nakata Syuhei , Nemoto Kohshichi , Sekiguchi Tadashi , Kotaki Yoshikazu
Published: November 2005

Experimental studies were performed on the interactions of a CO2 laser beam of long pulse duration (∼50 ns FWHM) and peak power up to 4×1012 W/cm2 with plasma blobs produced by this laser from a massive planar target of aluminum or polyethylene. Special attention was paid to the laser reflectivity (R) due to the stimulated Brillouin backscattering (SBS), in particular to the correlation between the SBS reflectivity and the e-folding scale-length for spatial plasma density variation (L

n
). It is shown that (1) the experimental L

n
-values are consistent with the theoretical ones predicted from an ellipsoidally-expanding self-regulating plasma model, and (2) taking those predicted L

n
-values into account, the experimental R-values agree well with those estimated from an existing simulation model, which is restricted to a relatively low percentage (15–20%) even for longer pulse duration.
Planar Dechannelling of Energetic Ions at Dislocations. III. Dechannelling at Edge Dislocations in Si
Authors: Kimura Kenji , Mannami Michihiko , Natsuaki Nobuyoshi
Published: November 2005

The planar dechannelling cross-sections of MeV ions at dislocations were calculated and the results were summarized in graphs, from which the dechannelling cross-section at a dislocation in an arbitrary crystal can be derived. The observed planar dechannelling cross-sections at edge dislocations in Si crystals implanted with phosphorus ions were compared with those derived from the calculated graphs, and the agreement between them was found to be satisfactory.
The Range of Diffusion Enhancement of B and P in Si during Thermal Oxidation
Authors: Mizuo Shoichi , Higuchi Hisayuki
Published: November 2005

The lateral range of oxidation enhanced diffusion (OED) of B and P in Si is investigated using selective oxidation at 1100°C with directly formed Si3N4 films as oxidation resistant masks and FZ Si crystals as substrates. It is found that this OED range of B agrees well with that of P and that the range increases with oxidation time. The value of the range is found to be much larger than previously. The results can be explained using a model in which the range is determined by interstitial diffusion.
Anomalous Diffusion of B and P in Si Directly Masked with Si3N4
Authors: Mizuo Shoichi , Higuchi Hisayuki
Published: November 2005

Diffusion of B and P in Si directly masked with Si3N4 films is found to have anomalous characteristics depending on temperature, time, and Si crystal growing method. The discrepancy in diffusion between CZ and FZ substrates under Si3N4 films is explained well assuming the Si–SiO2 interface acts as a sink for super-saturated interstitials. The Si–Si3N4 interface does not have such an effect. It is also found that super-saturated interstitials enhance the diffusion of B and P in CZ Si crystals directly masked with Si3N4 films.
Preparation and Properties of Amorphous Silicon Produced by a Consecutive, Separated Reaction Chamber Method
Authors: Kuwano Yukinori , Ohnishi Michitoshi , Tsuda Shinya , Nakashima Yukio , Nakamura Noboru
Published: November 2005

A new method of preparing a-Si film, in which each of the p, i, and n layers are deposited in consecutive, separated reaction chambers, is presented. It was confirmed experimentally that, in the conventional single reaction chamber method for a-Si film, the residual dopant gases which remain in the reaction chamber cause undesirable doping of the film, resulting in deterioration of the film quality. This undesirable doping can be avoided in the separated reaction chamber method. The photoconductivity of the i-layer prepared by this method was about 1×10-3 (Ω-1cm-1) in sunlight of AM–1 100 mW/cm-2. The best conversion efficiency of p-i-n a-Si solar cells prepared by this method was 6.91%.
Memory Switching in Amorphous Cd–Sb Films
Authors: Kawamura Yutaka , Kashiwaba Yasube , Ikeda Toshio
Published: November 2005

Amorphous Cd–Sb films with a Cd content of about 20% can be switched from a high-resistance state to a low-resistance state by the application of a dc or pulsed bias. Microanalysis of the switched region and observation of the growth of the dendritic filament from the negative electrode suggest that the migration of Cd ions is responsible for forming a conducting channel in the memory switching. The mechanism of the memory switching is explained as follows. First, a Cd speckle appears at the negative electrode, and then Cd dendrite develops from it. When the Cd dendrite just bridges both electrodes, a large current flows and the thermal effect extends to the surrounding region, creating a channel.
Formation of Vapour-Deposited SnO2 Thin Films Studied by Rutherford Backscattering
Authors: Yamazaki Toshinari , Mizutani Uichiro , Iwama Yoshiro
Published: November 2005

SnO2 films were prepared by evaporating SnO or SnO2 powder onto substrates kept at various temperatures. The composition x for “as-deposited” films was determined by RBS and was found to have a wide range of values between 1.0 and 1.6, depending on the evaporation conditions. SnO2 film was formed by annealing “as-deposited” SnO2 film in an O2 atmosphere. With increasing annealing time, x increased, finally reaching the stoichiometric value of 2.0, and the complete formation of SnO2 was confirmed by X-ray diffraction and electron microscopy. It was also found that oxygen atoms penetrate into the film with a concentration gradient in the depth direction of the film. The electrical conductivity and Hall coefficient were measured for specimens annealed at 550°C for various time intervals.
Deep Level Fourier Spectroscopy for Determination of Deep Level Parameters
Authors: Ikeda Kousuke , Takaoka Hidetoshi
Published: November 2005

A new technique called deep-lebel Fourier spectroscopy (DLFS), is proposed. This is an efficient and convenient method for evaluating deep livels in semiconductors. The technique is presented with a frequency space analysis for the case of exponential capacitance transients. Taking the Fourier transforms of the transient capacitance values, the deep level emission rate is determined in sequence from various numerical calculations of the Fourier coefficients. This method makes it possible to analyze the deep level accurately and automatically without judgements of the peaks in the spectra. Computer simulation and experiments using the method for a p-type Si Schottky diode are demonstrated. Finally, a comparison is made with the DLTS method.
A Model for Dielectric Breakdown in Plasma-Polymerized Styrene Thin Films
Authors: Hikita Masayuki , Matsuda Akinori , Nagao Masayuki , Sawa Goro , Ieda Masayuki
Published: November 2005

A new, simple breakdown model is presented as a result of experiments on plasma-polymerized styrene thin films. In this model, the current is controlled by Fowler-Nordheim tunnelling emission from the cathode, and bulk breakdown is governed by an impulse thermal process. The numerically-calculated values, disregarding the space charge, can be fitted to the dependence of the electric strength on temperature, field rise rate and prestress and are also consistent with all the experimental results. Also, steady-state avalanching is considered as a possible mechanism for bulk conduction. It is found that provided the mobility of positive charges is beyond a certain value, hardly any space charge is formed, giving a physical basis for neglecting the space charge. Also, impulse thermal breakdown can occur before a negative resistance appears. The parameters involved in the model are also discussed.
Current Limitation Induced by Infrared Light in n-Type GaAs Thin Layers on Semi-Insulating Cr-Doped GaAs
Authors: Kitahara Kuninori , Nakai Kenya , Shibatomi Akihiro , Ohkawa Shinji
Published: November 2005

The effect of infrared light on current was studied in n-type GaAs thin layers with FET-type structures. Three kinds of sample, formed by VPE, MBE and ion-implantation, were used to compare the effect from different interface states. From the current-voltage characteristics and carrier density profiles, it was determined that the current limitation by IR light is caused by the photoionization of traps and an extension of the interface depletion layer into the n-type layer. Four traps (E
c-0.8 eV, E
c-1.0 eV, E
v+0.7 eV and E
v+0.88 eV) were obtained from the photoresponse spectra. These traps are attributed to deep levels located in the semi-insulating GaAs substrates.
Some Relationships between Dosimetric Quantities in Photon and Electron Beams
Authors: Shiragai Akihiro , Noda Yutaka , Maruyama Takashi
Published: November 2005

Theoretical considerations of photon and electron dosimetry with general cavity are attempted on the basis of partitioning the kerma into its collisional part and its radiative part. A necessary and sufficient condition for the existence of charged-particle equilibrium in a material irradiated by photons is the equality of the collisional kerma with the absorbed dose. The exposure can be determined indirectly without restriction on the photon energies, if a quantity such as the W-value or G-value of the cavity material of the dosimeter is known. The absorbed dose can also be measured by using a dosimeter calibrated in terms of exposure, air kerma, or absorbed dose in the medium. During exposure calibration, air-kerma calibration, or exposure measurement, a material equivalent to the cavity wall must be used as the build-up cap material.
Silicon-Germanium-Boron Ternary Amorphous Alloy
Authors: Murase Katsumi , Takeda Akitsu , Mizushima Yoshihiko
Published: November 2005

Highly conductive ternary amorphous films are prepared by thermal decomposition of silane-germane-diborane mixtures in a low-pressure furnace at 500°C. The conductivity of the amorphous silicon-germanium-borom alloy exceeds the previously obtained limit for amorphous silicon, and increases with increasing germanium content. The d.c. conductivity and the Seebeck coefficient are measured at above room temperature. Measurements of the a.c. conductivity, optical absorption and E.S.R. are made at room temperature. The carrier transport is well described by a variable-range-hopping model. Evidences for a band model similar to that for the semimetal are proposed for the ternary amorphous alloy. In a higher germanium content film, the structure transforms into a microcrystalline one. The conductivity of microcrystalline silicon-germanium-boron alloy attains 103 S·cm-1.
Correlation between Frequency Fluctuations of a Quartz Oscillator and Temperature Fluctuations
Authors: Noguchi Yasuaki , Teramachi Yasuaki , Musha Toshimitsu
Published: November 2005

Frequency fluctuations of 5-MHz, 5th-overtone, piano-convex AT- and IT-cut quartz oscillators were measured with reference to a Cs oscillator (HP 5061A) while the oscillators were kept in a temperature-stabilized oven at Fourier frequencies from 10-2 Hz down to 10-6Hz. A power spectral density of the frequency fluctuation consists of three parts due to dependence on the Fourier frequency f, which are proportional to 1/f
2, 1/f and to f
0. The parts in proportion to 1/f
2 and f
0 are found to be related to the temperature fluctuation through static and dynamic temperature coefficients of the oscillation frequency. However, the 1/f part is found to be uncorrelated to the temperature fluctuation.
Composition Control of CdSxSe1-x Thin Layers Grown on CdS Substrate by a Solid-State Diffusion Technique
Authors: Mochizuki Katsumi
Published: November 2005

CdS
x
Se1-x
layers with graded-composition were grown on a CdS substrate by a solid-state diffusion technique. Efforts were made to control the surface composition X of the growth layers CdS
x
Se1-x
by heat-treating the CdS substrate under independently-regulated partial pressures of sulfur and selenium with a fixed partial pressure ratio (P
S2/P
Se2). The results confirmed that the surface composition X was controlled successfully over a wide composition range of CdS
x
Se1-x
.
Attempts were also made to control the deviation from stoichiometry of the surface layers with a fixed composition X.
Electrochromic Memory Degradation in WOx–LiClO4/PC Cells
Authors: Morita Hiroshi
Published: November 2005

Electrochromic memory degradation in Li
y
WO
x
has been investigated. When the external circuit connection has a resistor, which is important for a practical display use, the degradation mechanism has been explained by the capacitor discharge model. This model presents an estimation method for determining capacitance and EMF (electromotive force) for a cell. In the case of an open circuit, it has been proved that the simple diffusion theory could be adopted. Several factors, which improve the electrochromic open-circuit memory, have been considered.
Note on the Analysis of DLTS and C2-DLTS
Authors: Tomokage Hajime , Nakashima Hiroshi , Hashimoto Kimio
Published: November 2005

The difference in the peak temperatures of DLTS and C2-DLTS is discussed with reference to the measurement of deep levels in semiconductors. The emission rate of a trap level can be accurately determined when the peak temperature observed in DLTS agrees with that in C2-DLTS. When the peak temperatures disagree, the trap depth and trap density cannot be determined correctly, and the junction profile and trap density have a great effect on the peak temperatures of DLTS and C2-DLTS. These phenomena appear in DLTS and C2-DLTS measurements on Au-doped Si p+n diodes. It is necessary to use C2-DLTS together with DLTS in the study of deep impurities in semiconductors.
Optical Properties of Williams Domain
Authors: Hirata Shoji , Tako Toshiharu
Published: November 2005

There are three focal positions in Williams domain for microscopic observation by normal incident beam. The two focal positions above Williams domain correspond to the real images, and the one below to the imaginary image. The spacing between two neighboring real image lines is uniform but that between two neighboring imaginary image lines becomes alternately larger and smaller. The cause of these phenomena is made clear by considering the refraction of rays in Williams domain.
Effect of Oxygen on Compact CW-HCN Laser
Authors: Makiuchi Masao , Kawamura Mitsuo
Published: November 2005

Experimental studies showing the effect of oxygen on the output power of a compact CW–HCN laser are described. Oxygen is added to the active gas medium (CH4+N2), and when the oxygen is introduced under optimum conditions, an output power of about 48 mW is obtained at 337 µm.
Fluorescence Simulation in Anthracene Crystal and Its Relation to Exciton Distribution
Authors: Shimura Hiroshi , Ohba Yujiro
Published: November 2005

We have simulated the change in exciton distribution and fluorescence from a crystal surface, using an anthracene single crystal irradiated by an N2 laser pulse. The change in the excition distribution in the sample is considered to occur by three processes. These are natural decay, exciton diffusion, and the reabsorption effect. The exciton distribution becomes uniform as time passes after irradiation. The results of the simulation agree fairly well with the experimental results on decay times at typical wavelengths of fluorescence and time-resolved fluorescence spectra. It is also confirmed that the time dependence of the reabsorption effect depends on the change in exciton distribution.
NbN Films Prepared by Magnetron Sputtering
Authors: Akune Tadahiro , Sakamoto Nobuyoshi , Shibuya Yoshio
Published: November 2005

NbN films on sapphire or copper substrates have been prepared by magnetron sputtering in argon-nitrogen atmospheres. The highest transition temperature, T
c=15.7 K, was achieved with a film sputtered on a sapphire substrate at a substrate temperature T
s=800°C and a partial nitrogen pressure P
N2
=5×10-3 Torr. Uniform films with transition width narrower than 0.4 K were prepared with good reproducibility by this method. A short NbN tape of metallic luster stripped off from the copper substrate still showed a T
c of ∼15 K even after being bent to a radius of curvature as small as 6 mm. These results indicate that magnetron sputtering is useful for preparing NbN films and long NbN tapes.
Chloromethylated Polystyrene as Deep UV and X-Ray Resist
Authors: Imamura Saburo , Sugawara Shungo
Published: November 2005

The deep uv and X-ray lithographic characteristics of high-performance negative electron resist chloromethylated polystyrene (CMS) were investigated. The sensitivity and resolution of a series of CMS's synthesized from nearly monodispersed polystyrene were evaluated as functions of molecular parameters. In CMS with a molecular weight of 1.8×105 showing a resolution better than 1.5 µm, a high sensitivity of 29 mJ/cm2 to X-rays and a sensitivity to deep uv about 40 times higher than that of PMMA was achieved. This high sensitivity is attributed to the high reactivity of the chloromethyl group, as verified by the high G value of CMS (5.4), 50 times larger than that of polystyrene. In contrast to most negative resists, where oxygen in air depresses the sensitivity, the sensitivity of CMS is hardly affected by the atmosphere. The sensitivity and resolution in the deep uv system are particularly affected by light absorption, because CMS exhibits strong absorption between 200 to 300 nm.
Non-Newtonian Viscosity of a Concentrated Suspension of Deformable Shell Particles
Authors: Murata Tadayoshi
Published: November 2005

The effects of the deformation of suspended particles on the viscosity of a concentrated suspension are investigated theoretically. The suspension consists of neutrally-buoyant particles suspended uniformly in an incompressible Newtonian fluid. The suspended particles are incompressible Hookean shells filled with an incompressible Newtonian fluid and are spherical in shape in their undeformed state. The free surface cell model proposed by Happel is adopted. The equation of the surface of a particle in simple shear flow is obtained assuming that the deformation is very small. The viscosity of the suspension is obtained, based on the calculation of the energy dissipated per unit volume of the suspension. It is shown that the relative viscosity decreases as the shear rate increases.
Decay Times of Dispersed NO2 Fluorescence Excited in the Blue Region
Authors: Takezawa Sanzo , Sugimoto Nobuo , Takeuchi Nobuo
Published: November 2005

The time-resolved and dispersed fluorescence of NO2 excited by an N2-laser pumped tunable dye laser was investigated. A pseudocontinuum similar to that obtained by Sakurai and Broida (cw Ar+ and Kr+ lasers) was observed with excitation around the Huber-Douglas bands (454.5 nm). The decay times revealing the red shift were measured at 5 nm intervals (475–650 nm) with 10 nsec time resolution. The wavelength dependency is interpreted by means of the step ladder model by Donnelly et al. The signal-to-noise ratio is greatty improved by taking the average of 1000 laser shots for the fixed wavelengths.
High Resolution Stark Spectroscopy of H2CO at 3.51 µm by Saturated Absorption
Authors: Siio Itiro , Ohtsu Motoichi , Tako Toshiharu
Published: November 2005

Precise measurements were carried out on the Stark effect of the vibration-rotation transition 51,5(v=0)-60,6(v
5=1) in H2CO using a low-noise, stable He–Xe laser at 3.51 µm. The intracavity saturated absorption technique was employed to improve the resolution.
Eight of the allowed transitions were resolved and the small Stark coefficients were determined with high accuracy under a maximum applied field strength of 4.39 kV/cm. Furthermore, the first observation of six cross resonance lines in this transition is reported.
Inhomogeneous Distributuon of Dislocations in Phosphorus-Diffused Silicon
Authors: Itoh Nobuo , Nakau Tanehiro
Published: November 2005

CZ-silicon wafers subjected to phosphorus diffusion to a relatively deep diffusion depth (X
j=8 µm, C
s=1020 cm-3) using a POCl3 source are examined both by X-ray topography and by transmission electron microscopy. The diffusion corresponds to that for the formation of the emitter of the usual silicon power transistors. Diffusion-induced dislocations are inhomogeneously distributed, forming dislocation clusters about 50 µm wide at a depth of 4–6 µm. In the cluster, the maximum dislocation density is as high as 109 cm-2 at a depth of 4 µm and some dislocations reach the diffusion depth. Between the clusters, there are dislocation networks of relatively low density. The deep penetration of dislocations is attributed to the formation of the clusters.
Hydrogen Evolution from Polycrystalline Iron at a Constant Rate of Heating in Vacuum
Authors: Takeda Takao
Published: November 2005

A method for determining the amount of hydrogen evolved from iron samples using a constant rate of heating in vacuum has been developed. The method consists essentially of recording the flow rate of hydrogen evolved from a sample in a high-vacuum quartz tube, as a function of temperature, while the sample is heated at a constant rate from room temperature to 1000°C. The function is called the hydrogen evolution curve. The hydrogen evolution curves for several iron samples were studied.
Laser Resonance Scattering Studies of the Development of a Potential Step in a Low-Density DC Discharge in Hydrogen
Authors: Uchino Kiichiro , Maeda Mitsuo , Koga Kazuyuki , Sonoda Yoshito , Muraoka Katsunori , Akazaki Masanori
Published: November 2005

The populations of hydrogen atoms in the excited states (n=2 and 3) across the potential step in a DC discharge at low pressure have been measured by laser resonance scattering, with the laser tuned to the Balmer alpha transition (Hα, wavelength 656.3 nm). The results were used first to deduce the amplitude of the ion-acoustic turbulence, which was excited by the electron-ion streaming instability at the step. The amplitude was high enough to explain the anomalously high electrical resistivity there. Second, the results were used to discuss the cause of the luminosity jump, due to the behavior of electrons distributed in the potential of the ion-acoustic turbulence.
In-Diffusion and Annealing of Copper in Germanium
Authors: Kitagawa Hajime , Hashimoto Kimio , Yoshida Masayuki
Published: November 2005

The in-diffusion and anealing of copper in germanium are examined experimentally over the temperature range 600 to 805°C, and using the experimental results, discussions are made as to whether the dissociative mechanism or the kick-out mechanism is at work in these processes.
The experimental results support the theory that copper in germanium diffuses by the dissociative mechanism and the dominant point defects in germanium are vacancies.
Frequency Stabilization of AlGaAs Semiconductor Laser to the Absorption Line of Water Vapor
Authors: Tsuchida Hidemi , Ohtsu Motoichi , Tako Toshiharu
Published: November 2005

The absorption spectrum of water vapor in the (2, 1, 1) vibration-rotation band has been observed by using an AlGaAs semiconductor laser around 0.82 µm. The laser frequency was stabilized to one of the absorption lines by controlling the injection current. A frequency stability of 1.9×10-9≧σ≧1.1×10-11 was obtained for 10 ms≦τ≦500 s.
Q-Switched Nd:YAG Laser Annealing of an As Implanted Si Layer, and Its Application to a Buried Collector
Authors: Tsunoda Yoshihiro
Published: November 2005

An arsenic implanted Si layer has been annealed with a Q-switched Nd:YAG laser. As+ was implanted into a P-type (111) Si wafer (10 Ω·cm) at 100 keV and with a dose of 5×1015 cm-2. Optimum laser-irradiation conditions were found to be a energy density of 2.3 J·cm-2, 80% overlapping ratio, a repetition rate of 6 kHz, and a substrate temperature of 370°C. Under these conditions, the Si surface was smooth, As ions were almost fully activated, and residual damage was not observed.
The annealed layer was successfully applied to a buried collector in bipolar ICs. I
C–V
CE characteristics and isolation breakdown voltage in ICs were as satisfactory as in the case of conventional buried layer diffusion with arsenic-doped oxide.
The Transformation Kinetics of Amorphous Fe80B20 and Fe78B20Mo2 Alloys Using Electrical Resistivity Measurement
Authors: Asahi Nobuo , Fujimaki Tadashi , Koike Yoshimaro , Satoh Hiroko
Published: November 2005

The kinetics of the transformation of roller-quenched amorphous Fe80B20 and Fe78B20Mo2 alloys were investigated by electrical resistivity measurement, and the crystallization of these alloys was analyzed using the Jounson-Mehl-Avrami equation. From the isothermal annealing, the activation energies for crystallization were determined as 2.5 eV for Fe80B20 and 3.9 eV for Fe78B20Mo2.
A New AlGaAs/GaAs Heterojunction FET with Insulated Gate Structure (MISSFET)
Authors: Hotta Takashi , Sakaki Hiroyuki , Ohno Hideo
Published: November 2005

We have proposed and successfully fabricated a new type of field-effect transistor (FET) with an M-I-S-S structure, which consists of a metal gate, an Al2O3 insulator and a semiconductor-semiconductor (N-AlGaAs/GaAs) heterojunction, grown by molecular beam epitaxy. This device exhibited the following advantages. High effective mobility of electrons (µeff being 27,000 cm2/V·s at 77 K) and, the capability of sustaining a high gate voltage of up to 2 V in the forward direction. These features permit the use of MISSFETs in a variety of logic circuits with a larger logic swing and higher speed than those of MESFETs.
Modally Allotted Transmission of Optical Images through Homogeneous Planar Waveguides
Authors: Shono Yasuo , Inuzuka Tadao
Published: November 2005

It is found that an optical field from a two- or three-dimensional object can be transmitted through a homogeneous planar waveguide. In principle, the information from a portion of an optical image is allotted to a guided mode, and, for the planar multimode waveguide, the image transmission can be performed in such a way that a transparency inserted in the path of the wedge-shaped incident wave gives a shadowgraph sampled by m-lines. It is also shown that not only monochromatic but also colour images are transmitted without any chromatic aberration.
Solid-Phase Lateral Epitaxial Growth onto Adjacent SiO2 Film from Amorphous Silicon Deposited on Single-Crystal Silicon Substrate
Authors: Ohmura Yamichi , Matsushita Yoshiaki , Kashiwagi Masahiro
Published: November 2005

Single-crystal silicon films (200 nm thick) have been grown laterally by thermal annealing from amorphous silicon evaporated on a single-crystal (100) silicon substrate and implanted with ∼1016/cm2 Si, onto an adjacent SiO2 film by solid-phase epitaxy. The key requirements for this kind of lateral epitaxy appear to be a high-dose Si ion implanatation and low temperature (575°C) annealing for a long period in order to suppress the nucleation of randomly-oriented crystals on the SiO2 film.
Dispersion Parameters of the Refractive Index in III-V Compound Semiconductors
Authors: Takagi Toru
Published: November 2005

The dispersion parameters of the refractive index for binary III-V compounds were investigated on the basis of the single-effective-oscillator model proposed by Wemple and DiDomenico. New empirical equations for the parameters are proposed. They are useful for estimating the refractive index of multinary III-V compounds.
Josephson Tunnel Junctions with Nb, NbN Double-Layered Electrodes
Authors: Shoji Akira , Shinoki Fujitoshi , Kosaka Shin , Hayakawa Hisao
Published: November 2005

Josephson tunnel junctions with double-layered base and counter electrodes composed of Nb and NbN have been developed. The tunneling characteristics of the junctions and the effective penetration depth of the double-layered electrodes have been measured as a function of the thicknesses of the NbN and Nb films. It has been found that, by using the double-layered electrodes with a 100 nm-thick-NbN film and a 50 nm-thick-Nb film, the effective penetration depth can be sufficiently decreased without losing the large gap voltage of 4.4 mV and the small subgap conductance of 14 mV.
Microstructures and Hydrogen Bonding Environments of Sputter-Deposited a-Si:H Films
Authors: Noda Mikio , Ishida Hiroyuki
Published: November 2005

Microstructures and correlated hydrogen bonding environments of a-Si:H films prepared by RF sputtering have been investigated by means of transmission electron microscope and Fourier transform infrared spectrometer. The uniform film formed at low gas pressure during the deposition shows only two strong IR peaks due to SiH configuration. These peaks decrease, and both the peaks due to SiH2 configuration and voids in the films increase consistently with increasing gas pressure, indicating that the uniform portion surrounded by the voids included only SiH constituent and that this SiH2 constituent is formed on the surface of the uniform portion.
Operating Characteristics of Josephson Four-Junction Logic (4JL) Gate
Authors: Nakagawa Hiroshi , Sogawa Eiichi , Kosaka Shin , Takada Susumu , Hayakawa Hisao
Published: November 2005

A Josephson logic gate which consists of a closed loop with four Josephson junctions (4JL gate) and its operating characteristics are described. Devices have been fabricated using Pb-alloy technology with a minimum line-width of 5 µm. Gate operations with a current gain of 2 have been performed under complete input/output current isolation. A logic delay of 20 ps per gate has been measured in a chain of ten OR-gates for a fan-out of 1 with an average power dissipation of 3.7 µW.
On the RF Stabilization of MHD Instability
Authors: Itoh Kimitaka , Itoh Sanae-Inoue
Published: November 2005

The stabilization of the MHD mode by an rf wave with a perpendicular electric field is discussed. The increase in the drift velocity under rf oscillation stabilizes the MHD mode. The ponderomotive potential also works as a stabilization mechanism. The stabilization is expected to occur for both ωrf<\varOmega and ωrf>\varOmega (ωrf: rf frequency, \varOmega: ion cyclotron frequency), and is effective for shorter wave-length modes.
Geometrical Surface Wave Resonance at a Silicon (111) Surface in Reflection High-Energy Electron Diffraction
Authors: Hayakawa Kazunobu , Aizawa Noriyuki
Published: November 2005

The geometrical surface wave resonance condition in reflection high-energy electron diffraction (RHEED) is determined experimentally at the [1̄10] azimuth on a (111) surface of a silicon single crystal. The surface at this azimuth is a non-mirror plane of the crystal lattice for RHEED. The condition for this surface is verified as similar to that of a mirror plane.
Bragg Optics of a Logarithmic Spiral Surface
Authors: Sakayanagi Yoshimi
Published: November 2005

The logarithmic spiral is proposed as the form of the reflection surface of a crystal in X-ray optics. This curve has the special property that the angle between the normal and the radius vector is constant. In optical terms, the angle of incidence or the angle of reflection at any point is constant. Using these properties, we can collect X rays from an extended source to a point.
Whisker Growth during Epitaxy of GaAs by Molecular Beam Epitaxy
Authors: Morkoç H. , Stamberg R. , Krikorian E.
Published: November 2005

GaAs whiskers, many of them originating from one point, were observed on GaAs epitaxial layers grown by molecular beam epitaxy. Very small pools of Ga and/or In are believed to precipitate the whiskers which grow at a relatively rapid rate. This whisker growth process is similar to the vapor-liquid-solid (VLS) growth and may not necessarily be a result of any particular substrate defect.
A Short-Channel GaAs FET Fabricated Like a MESFET, But Operating Like a JFET
Authors: Morkoç Hadis
Published: November 2005

Normally-on GaAs field effect transistors (FETs) having 1 µm gate lengths and 4 µm channel lengths were fabricated in structures grown by molecular beam epitaxy (MBE). The unique part of this device is the very thin p
+/n
+ structure used to replace the conventional Schottky barriers. The device fabrication procedure is identical to that of a Schottky barrier FET (MESFET), but the devices exhibit characteristics similar to that of a junction field effect transistor (JFET). This new device, the “camel diode gate FET”, is expected to have applications in both logic and power devices.
Dynamic Study of Stacking Fault Tetrahedra Induced by Electron Irradiation in Copper Crystals
Authors: Fujita Hiroshi , Sakata Takao , Fukuyo Hideaki
Published: November 2005

The behavior of stacking fault tetrahedra (SFT) induced by electron irradiation in copper crystals has been investigated with a high-voltage electron microscope, concentrating especially on a) the growth of individual SFT, and b) the formation of linear arrays of SFT in the <100> direction. The effects of accelerating voltage, specimen temperature and dose rate of electrons on the behavior of SFT have also been examined.
Thermal Behavior of B, P and As Atoms in Supersaturated Si Produced by Ion Implantation and Pulsed-Laser Annealing
Authors: Itoh Kazuo , Sasaki Yoshisato , Mitsuishi Tomokuni , Miyao Masanobu , Tamura Masao
Published: November 2005

The heat treatment effect on supersaturated Si crystals with B, P, or As produced by high-dose ion implantation (8×1015 cm-2) and Q-switched ruby laser annealing (2.0 J/cm2) is investigated. The deactivation of excess B atoms becomes appreciable with a high-temperature heat treatment above 800°C, while deactivations of excess P and As atoms take place even at low temperatures of 300–400°C. The deactivation process of B atoms at such high temperatures was found to be a precipitation of B atoms with an activation energy of 3.2 eV using Hall effect measurements and transmission electron microscopy observation.
Observation of GaSe–SnO2 Heterostructure by XPS and AES
Authors: Tatsuyama Chiei , Ichimura Shoji , Iwakuro Hiroaki
Published: November 2005

The depth profile of the elemental composition of the GaSe–SnO2 heterostructure has been studied by XPS and AES. The SnO2 layer was prepared by spraying a solution of SnCl4 and SbCl3 in ethyl alcohol on to the the cleaved surface of GaSe heated to ∼400°C in air. After the solution had been sprayed on for about 5 secs., an SnO2 layer of thickness ∼460 Å formed, and a Ga2O3 layer of thickness ∼120 Å formed under the SnO2 layer. The Ga2O3 layer is a likely origin of the high-resistivity layer observed in the GaSe–SnO2 heterostructure.
Annealing Behavior of Zn-Doped p-Type InSe
Authors: Shigetomi Shigeru , Ikari Tetsuo , Koga Yutaka , Shigetomi Shigenobu
Published: November 2005

Photoluminescence measurements were carried out to study the annealing effect of Zn-doped p-type InSe. The diffusion constant of Zn atom along the c-axis in InSe was estimated to be D=2.7×107 exp
(-2.5 eV/k
T)cm2s-1 from the depth profiles of the 1.17 eV emission peak intensity. The isochronal annealing behavior of this peak showed that the activation energy for a dissociation of Se vacancy-Zn acceptor complex was 0.4 eV.
Phase Oscillation in Fiber Interferometer Caused by Light Impulse
Authors: Musha Toshimitsu , Katsumoto Toru
Published: November 2005

A fiber interferometer was used as a bolometer by coating the fiber surface black. Illumination of a very short light impulse was found to cause a damping oscillation of the optical phase in the fiber. The oscillation frequency was inversely proportional to a redius of curvature of the fiber. The origin of the phase oscillation is not clear but it seems to be related to a transverse vibration of the fiber which is excited by light impulse.
Analysis of Spontaneous Emission Effects on Spectra and L vs I Characteristics of Diode Lasers
Authors: Streifer W. , Scifres D. R. , Burnham R. D.
Published: November 2005

A theory based upon spontaneous emission coupling into the modes of diode lasers is used to derive longitudinal mode spectral width and optical power as functions of pumping current for both TE00 and TM00 modes. The analysis is shown to agree well with experimental results in the below threshold region of operation.
Optically Detected Magnetic Resonance in Fluorinated Amorphous Silicon (a-Si: H, F)
Authors: Sano Yoshio , Morigaki Kazuo , Hirabayashi Izumi , Konagai Makoto
Published: November 2005

Optically detected magnetic resonance measurements have been carried out at 2 K in a-Si: H, F. One radiative centre and two kinds of nonradiative centres have been observed and identified as being trapped holes (A centres) and two kinds of dangling bond centres with different environments, respectively.
Comments on the Nature of Electron Leakage in InGaAsP/InP Double Heterostructure
Authors: Chiu L. C. , Yariv A.
Published: November 2005

Non-radiative Auger recombination has been found to be capable of providing an alternative interpretation of the recent experimental observation of electron leakage in InGaAsP/InP double heterostructure.
Influence of Gap States on Basic Characteristics of a-Si:H Thin Film Transistors
Authors: Suzuki Tohru , Hirose Masataka , Osaka Yukio
Published: November 2005

The static characteristics of hydrogenated amorphous silicon thin-film transistors are theoretically studied based on the analysis of field effect in a-Si:H MOS structures. The TFT characteristics are obtained for typical cases of the gap state density distributions and the results showed that the slope of the state density distribution near and above the Fermi-level is a key factor to determine the on/off current ratio of a-Si:H TFTs.
Unstable Regions in III–V Quaternary Solid Solutions Composition Plane Calculated with Strictly Regular Solution Approximation
Authors: Onabe Kentaro
Published: November 2005

The behavior of unstable regions in the composition plane for III–V quaternary solid solutions made from among Al, Ga, In, P, As and Sb is analyzed, based on the strictly regular solution approximation for solid solutions. Temperature dependences of spinodal isotherms at 400–1000°C show that unstable regions cover a wide range of compositions. It is suggested that composition ranges exist where the spinodal temperature exceeds the melting point, so that such solid solutions can never be grown by near-equilibrium growth methods. Positions of quaternary critical points in the composition plane are also shown.
Collective Acceleration of Barium Ions in a Preformed Anode Plasma
Authors: Masuzaki Masaru , Tamagawa Yoh-ichi , Kamada Keiichi , Watanabe Seiichi , Kawasaki Sunao , Kubota Yusuke , Nakanishi Takashi
Published: November 2005

Barium ions in a preformed anode plasma were collectively accelerated up to a peak energy of 270 MeV (2.0 MeV/amu) using an electron beam pulse with peak energy of about 0.4 MeV, peak diode current 16 kA and pulse-width of 10 ns (FWHM).