bluuebunny/crossref_metadata_2025 huggingface dataset:
Heavy Wall Bubble
Authors: Konishi Susumu , Shimaya Shohichi
Published: November 2005

Static and dynamic properties of a heavy wall bubble, which has a statically stable horizontal Bloch line, have been studied for a 5 µm bubble garnet film. The heavy wall bubble shows translational velocity lower than the normal bubble, and the static bubble collapse field is also lower than that for the normal bubble by 1.1 Oe.
X-Ray Photoelectron Spectroscopy of Ag- and Cu-Doped Amorphous As2Se3
Authors: Ueno Tokihiro , Odajima Akira
Published: November 2005

X-ray phototelectron spectroscopy was used to determine the binding energies of the core electrons in Ag- or Cu-doped amorphous As2Se3 films. Chemical shifts of the constituent elements indicate the electron transfer from Ag or Cu to As and Se upon doping. Charged defects are induced to As-Se bonds. The mechanism of the migration of Ag and Cu in amorphous As2Se3 is discussed.
Application of a Position-Sensitive Proportional Detector to Mössbauer γ-Ray Diffraction
Authors: Kashiwase Yasuji , Minoura Masayuki
Published: November 2005

A linear position-sensitive proportional detector with sensitive volume 40 mm×8 mm×8 mm was tested for Mössbauer 14.4 keV γ-rays from Co57. The space resolution 0.25 mm and counting efficiency 65% have been obtained under the condition of 2.5 atmospheric pressure of a mixed gas of krypton 90% and methane 10%, and accelerating voltage 2.6 kV. The detector was successfully applied to separate the inelastic background from 200 Bragg peak of a lithium fluoride crystal with energy resolution of 10-8 eV by measuring the intensity with the Mössbauer source and the nuclear resonance absorber out of and in resonance.
A New Breakdown Phenomenon in Fine Structured VLSI Circuits
Authors: Miyamoto Kazutoshi , Matsumoto Heihachi , Ohbayashi Yoshikazu , Ohkura Isao , Matsumura Hiroshi
Published: November 2005

In fine structured n-channel MOS VLSI circuits, it is unavoidable that the n+ diffusion layer for the power supply line (VDD) is located near that for the ground line (VSS). The breakdown voltage between VDD and VSS is reduced significantly by the substrate current generated in the surrounding MOSFET's. The resultant current flowing from VDD to VSS becomes large enough to cause various kinds of catastrophic destructions. This phenomenon is well explained by considering the effect of the increased substrate potential of the parasitic VSS-substrate-VDD bipolar transistor.
Epitaxial Growth of SOS Films with Amorphous Si Buffer Layer
Authors: Ishida Makoto , Ohyama Hidenori , Sasaki Shuzo , Yasuda Yukio , Nishinaga Tatau , Nakamura Teturo
Published: November 2005

A new method of SOS epitaxial growth is proposed for the improvement of the crystalline quality. The method consists of two process steps: (1) a sapphire surface is first covered with a thin amorphous Si layer prepared by sputtering, and (2) Si CVD is then carried out, which effectively avoids various problems which occur in the early stage of film growth. We have succeeded in obtaining the epitaxial layer of Si on the sapphire substrate covered with an amorphous Si buffer layer (less than 100 Å). A smooth surface of silicon is obtained on the buffer layer in spite of a slow growth rate (∼550 Å/min), a high growth temperature (∼1000°C), and a thin film thickness (0.38–0.66 µm).
Preparation of Perpendicular Magnetic Co-Ru Films by an RF Sputtering Method
Authors: Hirono Shigeru , Maeda Yasushi , Hatakeyama Iwao
Published: November 2005

The crystallographic orientation and magnetic properties of sputtered hcp Co-Ru films have been studied. The [101̄0] orientation was dominant for the initial stages of film formation, but increasing film thickness gave rise to the high [0001] orientation normal to the film surface. The Co-Ru films with the high [0001] orientation had a columnar structure. Co-Ru films with a thickness of over 2 µm showed the perpendicular magnetic state.
Effect of Cr Concentration on Electrical Properties of Cr-Doped Semi-Insulating GaAs Substrates
Authors: Udagawa Takashi , Nakanisi Takatosi
Published: November 2005

The chromium concentration in semi-insulating GaAs substrates and its distribution along Cr-doped ingots have been measured by flameless atomic absorption spectrophotometry. When the Cr concentration is lower than a certain value, the Cr distribution can be approximated by the normal freeze equation. Whereas at higher Cr concentrations, the measured distribution deviates from the equation probably due to Cr precipitation. The Cr concentration is found to be closely correlated with leakage currents in the substrates and with activation efficiencies of 28Si ions implanted directly into the substrate.
A New High Resolution Negative Electron Resist Chloromethylated Poly-α-Methylstyrene (αM-CMS)
Authors: Sukegawa Ken , Sugawara Shungo
Published: November 2005

A new negative electron resist chloromethylated poly-α-methylstyrene (αM-CMS) was synthesized from nearly monodisperse poly-α-methylstyrene. αM-CMS has the highest contrast (γ=2.5–3.0) among the known negative polymer resists and has high sensitivity (3–33 µC/cm2). Sufficient resolution for a 1 µm pattern fabrication process was demonstrated. Submicron patterns as small as 0.1 µm were obtained in 0.4 µm thick αM-CMS on a solid substrate, suggesting that the ultimate resolution of the resist is better than 0.1 µm. Excellent thermal stability and high dry-etching durability assure wide application of αM-CMS in electron beam lithography.
Origin of the Ev+0.51 eV Level in GaAs
Authors: Ikoma Toshiaki , Takikawa Masahiko
Published: November 2005

From an electron beam irradiation and annealing experiment on LPE GaAs, we have shown that the E
v+0.51 eV level appeared in Fe-doped wafers only after irradiation and annealing at 200 C. Thus it is pointed out that the Ga-vacancies are necessary for Fe to form such a deep state in GaAs.
High Electron Mobility Transistor Logic
Authors: Mimura Takashi , Joshin Kazukiyo , Hiyamizu Satoshi , Hikosaka Kohki , Abe Masayuki
Published: November 2005

A high electron mobility transistor (HEMT) logic is described. Ring oscillators with enhancement-mode switching and depletion-mode load HEMTs with a 1.7 µm-gate length have been fabricated to assess logic performance capability. Switching delays down to 56.5 ps at room temperature and down to 17.1 ps at liquid nitrogen temperature have been obtained. The switching delay of 17.1 ps is the lowest of all the semiconductor logic technologies reported thus far.
The Temperature Dependence of Short Range Order in Amorphous Solid Polymers
Authors: Numakawa Mikio , Yoda Osamu , Odajima Akira
Published: November 2005

Trans fractions in molecular chains of ethylene-propylene random copolymer (EPRC) and γ-ray irradiated polyethylene (PE) have been estimated from the observed X-ray scattering curves using our recently proposed method, in which the observed intensity curves are compared with a simulated curve for amorphotized PE. The solid state intrachain order of these materials increases with decreasing temperature in the same manner as in an isolated state. The interchain order also increases at -140°C, compared with the value at room temperature for EPRC but there is no detectable change in the case of irradiated PE. The latter seems to be due to the interchain cross-linkings.
The Hydrogen Balmer- α Line Profile in RF-Discharge Plasmas
Authors: Matsunaga Kouzi , Kadota Kiyoshi , Fujiwara Masami , Fujita Junji
Published: November 2005

The spectral line profiles produced by neutral hydrogen atoms have been measured using a high resolution Fabry-Perot Interferometer. The Hα line 6563 Å is found to have an asymmetric profile in non-magnetized and low density plasmas. The line profile calculated taking into account the fine structure of the Hα line shows a reasonable agreement with the experimental results. The atom temperature obtained from the Doppler broadening is about 0.1 eV.
Two-Photon Photoemission and Band Symmetry in ε-GaSe
Authors: Kasuya Atsuo , Nishina Yuichiro
Published: November 2005

Polarization dependence of the two-photon photoemission spectrum has been measured in a layer-type semiconductor ε-GaSe for nitrogen laser excitation. This is the first demonstration that the present technique provides the means for determining the absolute energy level with respect to vacuum and symmetry of the energy band. The result of our analysis is consistent with the band structure calculation of Schlüter et al.
Analysis of Intrinsic Saturable Absorption in InGaAs/InP Diode Lasers
Authors: Yamanishi Masamichi , Suemune Ikuo , Mikoshiba Nobuo
Published: November 2005

The authors have developed a theory, based on a saturable absorption model due to intervalence-band transitions, to explain the observed acoustic signal and light-output-current characteristics in InGaAsP/InP diode lasers. The experimental results are explained satisfactorily by the present theory. The saturated loss coefficient, estimated from our theory, is in good agreement with the internal loss coefficient in the good lasing region determined from the frequency of transient relaxation oscillation in InGaAsP/InP diode lasers by Walpole et al.
Adhesion Failure of PVD Films Caused by Repeated Bending of Substrates
Authors: Kuwahara Kaizo , Fujiyama Hirokazu , Nishimura Akinori
Published: November 2005

A method to evaluate the adhesion of PVD films was devised. Bi, Al and SiO films of various thicknesses were thermally evaporated onto copper or mild steel substrates. The substrate was subjected to repeated plastic bending. The adhesion failure life (bending cycles until the film-peeling) was taken as a measure of the adhesion. It was found that this method gave a result analogous to that obtained from the conventional method using adhesives. It was further confirmed that this method was applicable when the adhesion was so strong that the conventional method failed.
Silicon Nitride Single-Layer X-Ray Mask
Authors: Sekimoto Misao , Yoshihara Hideo , Ohkubo Takashi , Saitoh Yasunao
Published: November 2005

In the low pressure chemical vapor deposition process, preparation of silicon nitride with low film stress and low refractive index is investigated as a function of deposition temperature and reactant gas ratio SiH2Cl2/NH3. The silicon nitride film with a stress of 15 kg/mm2 and refractive index of 2.3 is formed at the deposition temperature of 850°C and the SiH2Cl2/NH3 ratio of 4/1.
Using the film as an X-ray mask, a silicon nitride single-layer X-ray mask is realized, which has a 30 ×30 mm window and has high transparency to visible light.
The g-Values of Defects in Amorphous C, Si and Ge
Authors: Ishii Nobuhiko , Kumeda Minoru , Shimizu Tatsuo
Published: November 2005

The g-values of the ESR signal have been calculated for dangling bonds in amorphous C, Si and Ge and for weak bonds in amorphous Si by using the EHT method. Effects on g-values of changing the bond angle, bond length and dihedral angle have been calculated and found that the change of g-values due to fluctuations of the amorphous structure is dominated by the change of the bond angle. Although the calculated g-values depend on the cluster size, the results are useful for qualitative considerations on the dangling bonds and the weak bonds.
Difference in the Mechanical Strengths of Dislocation-Free Crystals of Czochralski Silicon and Float-Zone Silicon
Authors: Sumino Koji , Yonenaga Ichiro
Published: November 2005

The mechanical behaviors of dislocation-free crystals of Czochralski silicon and float-zone silicon are investigated as functions of the surface condition and the stressing rate. No difference in the yield strength is observed between the two types of crystals with chemically polished surfaces. On the other hand, the yield stress is measured to be higher for Czochralski crystals than for float-zone crystals at low stressing rates when the surfaces are abraded with carborundum. The results are interpreted in terms of the locking effect of dislocations by oxygen atoms.
Amplification Property of an Electron-Beam Pumped KrF Laser
Authors: Fujiwara Etsuo , Kato Yoshiaki , Yamanaka Chiyoe
Published: November 2005

Amplification property of an electron-beam pumped KrF laser at the pumping power of 3.5 MW/cm3 has been measured. Waveform of the amplified laser pulse has been analyzed and small signal gain coefficient and saturation intensity have thus been determined. It is confirmed that the production rate of the upper laser state follows very closely the time dependence of the energy deposition rate of the electron-beam in the laser gas and the quantum production efficiency is almost 100%. We find discrepancy between the measured saturation intensity and the calculated value based on the known kinetic constants and the simple two level laser model.
Measurement of the Magnetic Field in a Plasma Using an Impurity Probe Spectroscopy
Authors: Matsunaga Kouzi , Kadota Kiyoshi , Fujiwara Masami , Fujita Junji
Published: November 2005

The magnetic field strength has been obtained from the Zeeman splitting. Thermal He atoms, as an impurity, were injected into a low density (n
e∼5×1010 cm-3) hydrogen plasma produced by electron cyclotron resonance. A singlet line at 6678 Å from He atoms excited by the plasma electrons splits into a normal Zeeman triplet in the magnetic field. The line profile was measured with a high resolution Fabry-Perot interferometer. This diagnostic allows the determination of the Zeeman splitting at magnetic fields as low as 1.2 kG, lower than which the splitting is masked by the Doppler broadening of the injected atoms.
Enhancement of the Ion Current Density in Magnetically Insulated Ion Diodes
Authors: Miyamoto Shuji , Ozaki Tetsu , Imasaki Kazuo , Higaki Satoshi , Nakai Sadao , Yamanaka Chiyoe
Published: November 2005

An experiment on magnetically insulated ion diodes using a surface flashover anode is presented. The ion current density increased upon increasing the anode surface of the flashover source, and varied with the applied magnetic field. Enhancement of the ion current density by a factor of 3–4 occurs for an applied magnetic field of B
app/B
crit≃1.5.
Stable Mode-Locked Phosphate Glass Laser Oscillator
Authors: Tomie Toshihisa , Yano Masaaki
Published: November 2005

The performance of an actively mode-locked phosphate glass LHG8 laser oscillator accompanied with dye Q-switching is presented. It operates with good reproducibility (±2%) at high repetition rates of up to 4 Hz. With 4 mm thick and 1 mm thick etalons it produces 120 ps pulses of 500 µJ energy.
Effects of Fe Impurity in Vibrational Modes of CuInS2
Authors: Joshi N. V.
Published: November 2005

Lattice dynamical behaviour of CuInS2 with Fe impurity has been examined at 4.2 K by using Fourier transform spectroscopy. The observed modes are indentified. The mode located at 106 cm-1 is analysed by using a molecular model and was found to be originated by the Fe impurity at In sites. The peak situated at 155 cm-1 could not be explained with a one phonon excitation process and hence it is tentatively attributed to a two phonons absorption of the \varGamma4 mode or a combination mode of two TO modes.
Dispersion of Surface-Plasmon at Clean Si(001)-2×1 Surface
Authors: Iwasaki Hiroshi , Maruno Shigemitsu , Horioka Keiji , Li Sung Te , Nakamura Shogo
Published: November 2005

Inelastic low-energy-electron-diffraction measurements on a clean Si(001)-2×1 surface were made. Surface cleanliness was verified by Auger analysis. The elastic and inelastic energy intensity profiles of the (00) spot were measured to select incident conditions amenable to a kinematic analysis of the energy loss profiles. The surface-plasmon dispersion relation for Si(001)-2×1 surface was derived from the inelastic data using a conservation-law model. The dispesion curve decreases as the momentum parallel to the surface increases.
Efficient Amplification of an Optically Pumped NH3 Laser at 11.707 µm
Authors: Tashiro Hideo , Toyoda Koichi , Namba Susumu
Published: November 2005

An output pulse from a line-tunable NH3 laser has been amplified, yielding an energy of about 210 mJ in the 11.707 µm line. The energy conversion efficiency was about 26%. A small signal gain was estimated to be 4.4%/cm.
Anomalous Behavior in an InGaAs/InP Heterojunction Switching Photodiode
Authors: Kanbe Hiroshi , Ando Hiroaki , Yamauchi Yoshiharu , Susa Nobuhiko
Published: November 2005

The bias voltage dependence of the photocurrent and capacitance in an InGaAs/InP heterojunction switching photodiode were measured. The switching voltage, at which the photocurrent saturated, increased with increasing incident optical power and decreasing temperature. The capacitance at low frequency had a peak at a bias voltage slightly below the switching voltage. These results cannot be explained by theories previously reported on n-n isotype heterojunctions.
Acoustic Emission Associated with Tree Growth in Polyethylene
Authors: Yoshimura Noboru , Kudo Hideyuki , Noto Fumitoshi
Published: November 2005

The acoustic emission associated with tree growth in polyethylene was measured under an AC voltage. The acoustic emission and the partial discharge in the tree channels were compared, and it was found that the maximum charge of the partial discharge and the count rate of the acoustic emission are determined by the tree length. The count rate of the partial discharge pulses, however, is not determined by the tree length.
Cold Cathode Magnetron Injection Gun for Relativistic Electron Beams with a Long Pulse Width
Authors: Minami Kazuo , Sato Ikken , Matsui Toshiro , Kato Keizo
Published: November 2005

A cold cathode magnetron injection gun has been designed and constructed. A relativistic electron beam up to 200 keV, with beam current 150 A and pulse width 1 µs, is obtained. The parameters of the beam are located between those of REB diodes and those of usual hot-cathode magnetron injection guns. We have measured the electron beam in some detail, and the beam efficiency, i.e., the beam current divided by the cathode current, is about 40%. Part of the cathode current flows into the anode. It is found that, although the anode current is unavoidable, it does not necessarily cause breakdown between the electrodes. It is emphasized that the beam obtained in the present work will be extremely useful for devices involving relativistic electronics, e.g., gyrotrons, free electron lasers and intense X-ray generators.
A New Analyzing Method for Non-Uniformly Doped MOS Capacitor C-t Characteristics in Lifetime Evaluation
Authors: Miyake Masayasu , Harada Hiroyuki
Published: November 2005

A new analyzing method for non-uniformly doped MOS capacitor C-t characteristics in lifetime evaluation has been developed. By analyzing the C-t characteristic in combination with the doping profile, which can be measured by the pulsed C-V method, the generation lifetime can be evaluated. The method is applied to a low-dose boron implanted MOS capacitor, and the generation lifetime can be evaluated as a function of depth.
Molecular Beam Epitaxial Growth of Undoped Low-Resistivity InxGa1-xP on GaAs at High Substrate Temperatures (500–580°C)
Authors: Kawamura Yuichi , Asahi Hajime , Nagai Haruo
Published: November 2005

In
x
Ga1-x
P epitaxial layers have been grown on (100) GaAs substrates by molecular beam epitaxy. Undoped layers of low resistivity (0.1–1.0 Ω·cm) with mirror smooth surfaces could be obtained for substrate temperatures of 500–580°C. Precise composition control was possible by regulating the In/Ga beam intensity ratio even at these high substrate temperatures. The X-ray measurement results show that these epitaxial layers have a uniform composition in the growth direction. A photoluminescence spectrum without deep emission was obtained.
Angstroms Resolution in Se-Ge Inorganic Photoresists
Authors: Yoshikawa Akira , Hirota Shoichi , Ochi Osamu , Takeda Akitsu , Mizushima Yoshihiko
Published: November 2005

The intrinsic resolving power of a Se-Ge inorganic photoresist is investigated using a novel fine-particle technique. Ultra-fine resolution of up to about 10 Å is confirmed. Such a high resolution exceeding the optical limit is one of the essential features of amorphous chalcogenide materials.
The Effect of Annealing on the Electrical Properties of Selectively Doped GaAs/N-AlGaAs Heterojunction Structures Grown by MBE
Authors: Ishikawa Tomonori , Hiyamizu Satoshi , Mimura Takashi , Saito Junji , Hashimoto Hisao
Published: November 2005

The effect of annealing on the electrical properties of selectively doped GaAs/N-AlGaAs heterojunction structures grown by MBE has been studied. Very high electron mobility in this structure at 77 K decreased considerably after annealing at about 700°C. However, it remained at a high value even after annealing when the Si doping concentration in N-AlGaAs was reduced to about 1×1018 cm-3. These results are discussed in terms of diffusion of Si impurities doped in N-AlGaAs.
High-Rate Reactive Ion Etching of SiO2 Using a Magnetron Discharge
Authors: Horiike Yasuhiro , Okano Haruo , Yamazaki Takashi , Horie Hiromichi
Published: November 2005

A magnetron discharge has been used for high-rate reactive ion etching. A SiO2 wafer situated on the cathode was etched by scanning a rectangular permanent magnet under the cathode coupled with a power of 13.56 MHz which generated an intense plasma loop over the cathode. The SiO2 etch rate of 1.1 µm/min and the SiO2/Si selective ratio of 9.5 was achieved by employing CHF3 under a magnetic field of 1 k Gauss and an input rf power of 1.6 W/cm2. This condition lowers the ion bombarding voltage of 80 Å on the Si surface. The plasma scanning and an electrostatic chacking of the wafer to the wafer-cooled cathode produces an anisotropic etched feature without photoresist degradation.
A New Magneto-Optic Readout Technique with High Speed and High Sensitivity
Authors: Gomi Manabu , Abe Masanori , Nomura Shoichiro
Published: November 2005

A new magneto-optic readout technique is proposed, giving high-speed, highly-sensitive readout of magnetic information stored in a recording medium with a relatively small magneto-optic rotation power. This technique is essentially a polarization modulation technique (which gives highly-sensitive readout) combined with the differential method (which gives high-speed readout). The new technique enables us to detect a magneto-optic rotation angle as small as 9' at a signal-to-noise ratio (SNR) of 45 dB in a 100 kHz bandwidth at 3 mW laser power (λ
=632.8 nm). This value of the SNR is 15 dB larger than that obtained by the conventional differential method.
Quantitative Surface Atomic Geometry and Two-Dimensional Surface Electron Distribution Analysis by a New Technique in Low-Energy Ion Scattering
Authors: Aono Masakazu , Oshima Chuhei , Zaima Shigeaki , Otani Shigeki , Ishizawa Yoshio
Published: November 2005

A new technique for analyzing the quantitative surface atomic geometry and the two-dimensional surface electron distribution is reported. The remarkable effectiveness of this new technique is demonstrated for TiC(111).
ESR and IR Studies on a-Si1-xGex:H Prepared by Glow Discharge Decomposition
Authors: Morimoto Akiharu , Miura Takashi , Kumeda Minoru , Shimizu Tatsuo
Published: November 2005

This paper presents results on ESR measurement and IR absorption in a-Si1-x
Ge
x
:H films prepared by glow discharge decomposition. In as-deposited films, the number of Ge dangling bonds per Ge atom [Ge↑]/[Ge] is found to be larger than that of Si dangling bonds per Si atom [Si↑]/[Si] by a factor of 4–15 because of preferential attachment of H to Si. [Ge↑]/[Ge] is reduced by an increase in Si content because H bonded to an Si atom works not only as a terminator for Si dangling bonds but also as a structural softener in these films. The differences in [Ge↑]/[Ge] among samples with various Si contents become smaller with increasing annealing temperature.
A New Technique of Boron Doping in Si:H Films
Authors: Hamasaki Toshihiko , Kurata Hiroyuki , Hirose Masataka , Osaka Yukio
Published: November 2005

Very high doping efficiency of boron atoms in hydrogenated silicon has been achieved using the glow discharge of a SiH4-B2H6 mixture gas under conditions of a low concentration of SiH4 and application of magnetic field to the plasma column. A maximum conductivity of 7.8 Ω-1cm-1 has been obtained at a doping ratio of N
B2H6
/N
SiH4
=2.6%. This high conductivity is found to be related to partial crystallization of amorphous Si:H network.
ESR Study of the Incommensurate-Commensurate Phase Transition in [N(CH3)4]2ZnCl4
Authors: Suzuki Ikuo , Tsuchida Kazuaki , Fukui Minoru , Abe Ryuji
Published: November 2005

The temperature dependence of the ESR spectra of Mn2+ ions has been studied in the incommensurate phase of [N(CH3)4]2ZnCl4 crystal. The edge-singularity of the ESR spectra was analyzed in terms of an incommensurate spatial modulation of the fine structure tensor. The plane wave modulation model is a good approximation in the wide temperature range between T
I and T
c. The critical index β for the amplitude of modulation is 0.46±0.05 in this temperature range.
Non-Destructive Method for Measuring Cut-Off Frequency of a p-n Junction with a Chopped Photon Beam
Authors: Munakata Chusuke , Honma Noriaki
Published: November 2005

A solar cell fabricated on a p-type polycrystalline Si wafer has been irradiated with a chopped photon beam emitted by a light-emitting diode. The wavelengh of the beam is 559 nm. The chopping frequency of the beam is varied from 10 to 10,000 Hz, and a cut-off frequency of 130 Hz is obtained from the frequency dependence of the ac photovoltage, which is measured capacitively through a 15 µm-thick mylar film. The observed value agrees well with that obtained by the conventional method.
Measurement of Lattice Temperature during Pulsed-Laser Annealing by Time-Dependent Optical Reflectivity
Authors: Murakami Kouichi , Takita Kôki , Masuda Kohzoh
Published: November 2005

The Si lattice temperature during pulsed-laser annealing has been measured by an interference method, namely a time-dependent optical reflectivity measurement on SOS. This method utilizes optical interference effects between the light reflected from the Si surface and that from the Si-sapphire interface. It was found that the Si lattice temperature increased to at least approximately 1000°C during pulsed-laser annealing. Additionally, this work clarifies the temperature dependence of the refractive index n(T) of Si for a wavelength of 6328 Å, i.e.
n(T)=3.98+4.7×10-4
T(°C).
Fabrication of 80 nm-Wide Lines in FPM Resist by H+ Beam Exposure
Authors: Moriwaki Kazuyuki , Aritome Hiroaki , Namba Susumu , Karapiperis Leonidas
Published: November 2005

80 nm-wide lines in FPM resist have been fabricated by ion beam exposure through a Au mask with a very low dose of 3×10-7 C/cm2. The Au mask-pattern was fabricated by means of an oblique evaporation technique on FPM resist for irradiation by a 50 keV H+ beam. It was confirmed that the substrate did not affect the dissolution characteristics of the FPM after the ion beam exposure. These features lead to the possibility of applying various resists other than PMMA to nanometer-lithography, making good use of their high sensitivity and/or high resistance to dry etching.
Cd-Doping in InxGa1-xAsyP1-y Mixed Semiconductors Grown by Liquid-Phase Epitaxy
Authors: Fujita Shigeo , Matsuda Ken-ichi , Sasaki Akio
Published: November 2005

The doping characteristics and electrical properties of Cd-doped p-type In0.75Ga0.25As0.55P0.45 grown by a LPE method have been investigated. The distribution coefficient of Cd was about 3–4×10-3. The activation energy of the Cd acceptor level is between 4.2 and 13.7 meV, depending on the doping concentration employed. In n-InP/p-InGaAsP heterojunctions using Cd as a p-type dopant, the displacement of the junction position was barely observable. The minority carrier (electron) diffusion length in the p-type region with a hole concentration of 1×1018 cm-3 was estimated around 2.8 µm.
Observation of Acoustic Signals from Semiconductor Lasers
Authors: Suemune Ikuo , Yamanishi Masamichi , Mikoshiba Nobuo , Kawano Tadasu
Published: November 2005

Acoustic signals were observed from GaAs-GaAlAs double-hetero (DH) semiconductor lasers. The current-injection-induced acoustic (CIA) signals observed from channeled-substrate planar (CSP) lasers were saturated at the current levels less than the lasing threshold current, i.e., at 70–80% of I
th. In the current range of a kink in light output versus current characteristics, an anomaly was observed in the characteristics of CIA signals.
Punchthrough Effect Observed in the dc I-V Curves of a Josephson Tunnel Junction with Microwave Radiation
Authors: Koyanagi Masao , Endo Tadashi , Nakamura Akira
Published: November 2005

The punchthrough effect is used to calculate the dc I-V curves obtained from a Josephson junction irradiated by microwave radiation. Good agreement is obtained between the experimental and the calculated I-V curves.
2-D Grating Graphoepitaxy of Silicon Films from Silicon-Gold Supersaturated Solution
Authors: Mori Hidefumi
Published: November 2005

Orientation controlled silicon crystalline films were prepared on fused quartz substrates. The crystallization was performed by precitipation from a Si-Au supersaturated solution. One dimensional (1-D) surface relief gratings with a period of 1 µm and two dimentional (2-D) gratings with a cross angle of 60° were used to control the crystal orientation. Silicon films were better aligned on the 2-D gratings than on the 1-D gratings. The (111) crystal plane was parallel to the substrate plane.
Rayleigh-Taylor Instability in Nonuniform Pellet of Inertial Confinement Fusion
Authors: Abe Takashi , Niu Keishiro
Published: November 2005

In the imploding pellet of the inertial confinement fusion (ICF), the Rayleigh-Taylor (R-T) instability caused by the accelerating compression takes place at various places of the pellet. The effects of the nonuniform compression and the intrinsic nonuniformity of the pellet are investigated for the R-T instability. The analysis shows that the growth rate of the R-T instability remains unchanged within the first order of the ratio between the scale length of perturbations and of the nonuniformity.
Crystallization of Amorphous Sb1-xBix ( x ≤0.2) Films
Authors: Hashimoto Mituru , Ogihara Hideaki , Kambe Kenjiro
Published: November 2005

A study is made of the crystallization in amorphous films of Sb1-x
Bi
x
(x≤0.2) evaporated on a glass substrate. The crystal growth in films of thickness 70–500 Å is directly observed through an optical microscope. The substrate is maintained between 20°C and 60°C. With the increase in x the crystallization thickness and the growth rate extrapolated to the infinite thickness decrease. The activation energy for crystallization seems not to depend on x but has a tendency to increase with the decrease in film thickness.
Analytical Expressions for Specific Heats and Isentropic Exponent of High Temperature Gases. II. Air
Authors: Matsuzaki Ri'ichi
Published: November 2005

Exact analytical expressions for the specific heats and the isentropic exponent are obtained for partially-ionized air. The problem is reduced to the calculation of the derivatives of the concentrations with respect to temperature and density. The air is assumed to consist of eleven species: O2, N2, O, N, NO, O+, N+, NO+, O2
+, N2
+, and e-. A method for obtaining approximate analytical formulae is proposed for air including Ar and Ar+. Simplified analytical expressions at low temperatures where all the ionized species are neglected are also given. The results of the analytical expressions are in good agreement with a published table obtained by a numerical method over a wide range of temperature and pressure.
Precise and Easy Method of TDR to Obtain Dielectric Relaxation Spectra in GHz Region
Authors: Nakamura Haruki , Mashimo Satoru , Wada Akiyoshi
Published: November 2005

A new method of time domain reflectometry (TDR) is described. This “reference method” has made it possible to measure dielectric spectra of liquid samples in the GHz region more precisely and easily than the usual TDR method, taking in differences among the reflections from the air, a standard liquid and an unknown sample. The advantages of the method are demonstrated by measurements of dielectric spectra of alcohols and dilute polymer solutions, the critical frequencies of which are above 100 MHz.
Carrier Traps in Polyethylene Naphthalate (PEN): Photoelectret
Authors: Kojima Kenzo , Takai Yoshiaki , Ieda Masayuki
Published: November 2005

Electronic carrier traps in polyethylene naphthalate (PEN) were investigated by TSC and TL analysis in the temperature range from -196°C to 160°C. Two broad peaks were observed in the TSC and TL from PEN films illuminated with light of wavelength 360 nm at -196°C. The detrapping process was closely related to the molecular motions, the so-called γ and β relaxations. The apparent trap depths ranged from 0.1–0.5 eV.
Thin-Film Electroluminescent Device Employing Ta2O5 RF Sputtered Insulating Film
Authors: Kozawaguchi Haruki , Tsujiyama Bunjiro , Murase Kei
Published: November 2005

In order to fabricate low-voltage-driven high-brightness thin-film electroluminescent devices, the emission characteristics of devices employing low dielectric loss Ta2O5 RF-sputtered insulating films have been studied in comparison with those of devices employing Y2O3, Sm2O3 and Al2O3 deposited insulators. It was found that the devices employing Ta2O5, RF-sputtered films exhibited higher brightness, lower driving voltage and higher stability than the other devices. In addition, no aging was observed in the Ta2O5 insulated devices. These results indicate that the Ta2O5 RF-sputtered film is suitable as the insulating film in thin-film electroluminescent devices, and that the properties of the insulating film are closely related to the emission characteristics in such devices.
Generation of Ultrashort Light Pulses by Electronic Self-Phase Modulation
Authors: Yajima Tatsuo
Published: November 2005

A theoretical analysis is given for the temporal characteristics of optical pulses subject to self-phase modulation (SPM) in nonlinear media with a fast response time shorter than the optical period. The pulse shortening properties of these pulses in linear dispersive media are also calculated. The results are shown to be applicable to the generation of extremely short optical pulses in the subpicosecond and femtosecond ranges. A comparison with the other case based on conventional SPM with a much slower response is given.
A Temperature Controller for Experiments Using Adiabatic Demagnetization
Authors: Nara Koichi , Fujii Itsuhiro , Kaneko Kazuyuki , Ikushima Akira J.
Published: November 2005

An apparatus has been designed to control and stabilize temperature in the range 2–20 mK using the adiabatic demagnetization technique. Using a standard CMN demagnetization cell, the temperature of liquid 3He was stabilized within ±0.5 µK.
Comprehensive Studies on a Photoinitiated H2/F2 Laser Using Atmospheric Gas Mixtures with O2 Inhibitor
Authors: Watanabe Kazuhiro , Iyoda Mitsuhiro , Obara Minoru , Fujioka Tomoo
Published: November 2005

Theoretical calculations have been made of practical performance characteristics of an atmospheric, photo-initiated H2/F2 laser with O2 inhibitor, under various operating parameters (concentration, component ratio, and total gas pressure) which had been used in the experiment previously reported. These were compared with the experimental results. The calculated results are in good agreement with the extensive experimental data available. The effects of the O2 inhibitor on the HF laser output have been specially investigated in this paper. The decrease in HF laser output energy in the high-pressure region of over 1 atm of total gas mixture has been explained in terms of the competition between quenchins reactions by O2 and H2/F2 pumping chain reactions under weak initiation.
X-Ray Induced Current Transients in α-Form Polyvinylidene Fluoride
Authors: Mizutani Teruyoshi , Suzuoki Yasuo , Sugiura Nobuaki , Ieda Masayuki
Published: November 2005

X-ray induced current transients in polyvinylidene fluoride (PVDF) were measured. The initial decay of the induced conductivity after the termination of the X-ray irradiation was approximated by an exponential decay with time constant τ, and the characteristics of τ are discussed. τ was field-dpendpent and had a minimum around 200 kV/cm at 313 K. τ decreased with X-ray intensity under a low field, whereas it remained constant under a high field. These complicated phenomena could be explained consistently in terms of two different kinds of carrier traps, whose existence and field-dependence were reported in our previous study on X-ray-induced thermally-stimulated currents in PVDF.
Anomalous TSC and Space Charge in High-Density Polyethylene
Authors: Mizutani Teruyoshi , Oomura Tetsuro , Ieda Masayuki
Published: November 2005

An anomalous TSC flowing in the same direction as the charging current was observed in a high-density poly-ethylene (HD-PE) thermoelectret. The forming-temperature and field dependences of the TSC were measured, and the amounts of injected space charge in HD-PE specimens were also evaluated from the collecting-bias TSC. They were found to have a good correlation with the magnitudes of the peaks of the anomalous TSC. Numerical calculation revealed the appearance of an anomalous TSC peak originating from injected space charge under the blocking electrode condition. From these results, the anomalous TSC was concluded to be due to injected space charge and the blocking condition of the electrodes.
X-Ray Diffraction Study of the Melting of Benzene
Authors: Tohji Kazuyuki , Murata Yoshitada
Published: November 2005

The melting of benzene has been studied using an energy-dispersive X-ray diffractometer. Premelting phenomena have been observed in the intensity change of the Bragg peaks. The molecular motion in the crystal during the premelting process is discussed.
Stability of Streamer Chamber
Authors: Wada Toshiaki , Ogawa Masato , Takahashi Kaoru , Sugiyama Tsunetoshi , Kobayashi Shigeharu , Kohno Hirobumi
Published: November 2005

The quality of tracks obtained from a streamer chamber is studied through the measurement of the streamer brightness. The stability of streamer tracks depends on the value of the high voltage applied and its shape. By using a single conical-type spark gap as the pulse shaper, stable brightness of the streamer tracks is attained. The data on the streamer brightness are compared with the result by Bulos et al. and it is found that the brightness is more strongly affected by field parameters than in their result.
Dependence of Secondary Electron Emission Coefficients on z1 in Metal Targets under Bombardment with Bare Projectiles
Authors: Koyama Akio , Shikata Takashi , Sakairi Hideo , Yagi Eiichi
Published: November 2005

The secondary electron emission coefficients are measured in targets under bombardment with He2+, C6+, N7+ and O8+ ions at an energy of 6.2 MeV/amu, the backward secondary electron emission coefficients γback being measured for thick Al and Ag targets, and the backward and forward coefficients γback and γfor for an Au foil target. γback/z
2
1 decreases with z
1 in proportion to 1–0.005z
2
1. With the effective charge z
*
1, γfor/z
*2
1 shows a similar decrease with z
1. These decreases are caused by the decrease in the escape probability of secondary electrons from the surface with increasing z
1, that is, increasing specific electronic energy loss S. This result implies that the surface barrier height U depends on S. A mechanism for the ion-induced increase in U is proposed, and the difference between the way γback and S depend on the energy for N7+ ions is explained by considering this dependence of U on S.
Planar Dechannelling of Energetic Ions at Dislocations. II. Dechannelling at Misfit Dislocations in PbS/PbSe
Authors: Kimura Kenji , Sawada Shin-ichi , Mannami Michi-hiko
Published: November 2005

The planar dechannelling of MeV He ions at misfit dislocations formed on the interface of epitaxial bi-crystals of PbS/PbSe was measured. The dechannelling cross-sections at dislocations for (100), (110) and (111) planar channetiling were almost independent of the energy of He ions ranging from 0.6 to 1.7 MeV. Using the modified continuum model of channelling in a distorted crystal, this deviation of the cross-section from √E-dependence, where E is the energy of the ions, is interpreted as being due to the superposition of displacement fields of misfit dislocations.
Assessment of Radiographic Granularity by a Single Number. II. Interpretation of Conditional Entropy Hx(y) in the Bivariate Entropy Method
Authors: Fujita Hiroshi , Uchida Suguru
Published: November 2005

The meaning of conditional entropy H

x
(y) in the bivariate entropy method is interpreted theoretically. It is shown that H

x
(y) is related to the geometric mean of individual standard deviations of the output distributions when these are Gaussian. This interpretation is used to assess the radiographic granularity by a single number in terms of entropy. It is indicated that H

x
(y) in this application is related to the geometric mean of the RMS granularity and represents entropy granularity as defined in this paper. The results of the above analysis and application show that H

x
(y) in the bivariate entropy method is a significant measure of the average of the scatter in measured data.
Effect of Electron Traps on Residual Voltage in Chalcogenide Photoreceptors
Authors: Okuda Masahiro , Motomura Kota , Naito Hiroyoshi , Matsushita Tatsuhiko , Nakau Tanehiro
Published: November 2005

The effect of electron traps on the residual voltage in chalcogenide photoreceptors is discussed. In order to cancel hole traps in these photoreceptors and to decrease the residual voltage, it is useful to introduce electron traps.
It is seen from numerical calculation that, in the case of uniform distribution of the normalized electron trap density N
tn, the introduction of N
tn=1.0 decreases the the residual voltage to one tenth of N
tn=0.
On the other hand, in the case of exponential distribution of the normalized electron trap N
tn(x)=N
0exp
(-A
x), it is interesting that the residual voltage V
r is greatly influenced by the electron trap density at the interface of the substrate.
Dielectric and Piezoelectric Properties of 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 Single Crystals
Authors: Kuwata Jun , Uchino Kenji , Nomura Shoichiro
Published: November 2005

The dielectric, piezoelectric and elastic properties of 0.91(PbZn1/3Nb2/3)O3–0.09PbTiO3 single crystals have been investigated as functions of temperature and applied electric field. Two multiple phase transitions at 68°C and 178°C, the crystal changing from the rhombohedral ferroelectric phase to tetragonal ferroelectric and then to cubic paraelectric, have been observed. Both the transitions are of first-order, but both are slightly diffused. Significant increases in the dielectric, piezoelectric and elastic constants are observed at the lower transition point. In particular, the sample poled along the pseudo-cubic [001] axis reveals anomalously large piezoelectric and electro-mechanical coupling constants at room temperature in the rhombohedral phase (d
[001]//=1500×10-12 C/N, k
[001]//=0.92).
Photoconduction in Metal-Doped GeySe1-yGlasses
Authors: Chamberlain J. M. , Moseley A. J.
Published: November 2005

An investigation of photoconduction (PC) in bulk doped and undoped GeySe1-yglasses (y≤0.4) is reported between 1.2 eV and 2.8 eV between 50 K and 390 K. PC is predominantly by holes, even for 0.4≥y≥0.15 material, with a typical activation energy 0.20 eV. PC is increased significantly for low (0.1–1 at.%) In doping, and reduced for Fe and Cu doping. These changes, together with observed changes in dark currents and activation energies, are modelled in terms of gap-state impurity distributions. Persistent PC is observed which depends strongly onybut is doping independent. A model to explain this is outlined.
Diffraction of Light Waves in an Inhomogeneous and Anisotropic Medium
Authors: Kojima Kenji
Published: November 2005

Approximate solutions of Maxwell's equations in an anisotropic medium with the weak inhomogeneity are shown when monochromatic plane light waves are incident. One group of approximate solutions including the Raman-Nath diffraction in an anisotropic medium is derived by using the phase function method under the condition that the spatial variation of the medium is sufficiently small compared with that of the incident light waves. Another group of solutions derived by The use of the Born approximation includes both the normal Bragg diffraction and the abnormal one. The two solution types hold only in the neighbourhood of the boundary plane because of the conditions under which they are applicable.
The Reliability of Schottky Barrier Restricted GaAs/GaAlAs LEDs
Authors: Chin A. K. , Zipfel C. L. , Dutt B. V.
Published: November 2005

LEDs and diode lasers, using a Schottky barrier to restrict the current flow, have recently been reported. Devices with the current restricted by either a Schottky barrier (SB) or a dielectric layer have been shown to have similar performance but the reliability of SB devices has not been investigated. In this paper, the results of a reliability study on SB restricted GaAs/GaAlAs LEDs are presented. In comparison to the highly reliable dielectric isolated LEDs, SB restricted LEDs degrade fairly rapidly due to the interaction of Au and GaAlAs at the p-contact. During operation, Au from the heatsink migrates to the semiconductor and forms a AuGa alloy from which dark line defects initiate. By the use of a 1000 Å thick Pt or Pd barrier layer, Au migration is greatly reduced and the device lifetime increased. However, the thickness of the barrier metal must be further optimized before the SB device reliability is comparable to that of dielectric-isolated LEDs. In dielectric-isolated LEDs, degradation by Au–GaAlAs interaction is also shown to exist but only after long-term operation at elevated temperatures. Finally, since the processing and metallization for various stripe geometry lasers are similar to those used in our LEDs, GaAs/GaAlAs lasers should also degrade by these metal-semiconductor interactions.
Shubnikov-de Haas Measurements in N-Type Pb1-xSnxTe
Authors: Takafuji Yutaka , Narita Shin-ichiro
Published: November 2005

Relatively large n-type Pb1-x
Sn
x
Te single crystals with various x values (x=0–0.28) were prepared and the Shubnikov-de Haas oscillations were measured. The results indicate that the Fermi surface consists of four [111] spheroids whose anisotropies increase with decreasing band gap. The effective mass and effective g
*-values of the conduction band were estimated as functions of the alloy composition, and the results are analyzed by a simple two-band non-parabolic model, which gives the transverse momentum matrix element P
⊥=√0.58(1+0.211x)/2, and the longitudinal momentum matrix element P
//=√0.046(1-0.142x)/2, both in atomic units (a.u.).
Gas Plasma Etching of Chromium Films
Authors: Suzuki Yoshiki , Yamazaki Teruhiko , Nakata Hidefumi
Published: November 2005

The etching of Cr film was investigated employing mixtures of CCl4 with CO, CO2, or O2. The highest etch rate ratio of the Cr film to the photoresist was given by the combination of CCl4 with CO2, and the Cr film could be etched successfully without serious loss in the pattern width using this CCl4/CO2 mixture. It is speculated that O(3P) contributes to the etching reactions of chromium films. Spectrometry revealed that singlet oxygen radicals contribute to the decomposition reactions of the resist films in the plasmas. Using this novel gas plasma etching technique, photomasks for MOS LSI were made with good pattern width control.