bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse Photoemission Spectroscopy Study on the Oxidation of Titanium Thin Film
Authors: Konishi Ryosuke , Ikeda Satoshi , Osaki Tomoyuki , Sasakura Hiroshi
Published: February 2005

We fabricated an inverse potoemission spectroscopy system of an angle-integrated type. We observed the change in density of unfilled states of evaporated titanium on a polycrystalline Ti substrate. The clean surface spectrum shows a very prominent peak at 0.5 eV above the Fermi level. After 70L, it is considered that the mixed layer of Ti and surface oxide is formed. After 1500L, the spectra which is attibuted. We considered that the stable oxide layer is formed on the surface after 1500L to 50000L.
Secondary Battery Characteristics of Poly(p-phenylene vinylene) Derivatives
Authors: Kawai Tsuyoshi , Iwasa Toshinori , Kuwabara Takao , Onoda Mitsuyoshi , Yoshino Katsumi
Published: February 2005

Electrochemical characteristics of poly(2, 5-diethoxy-p-phenylene vinylene) film are investigated for use as a rechargeable electrode active material for a secondary battery. The Coulombic efficiencies in constant current chargedischarge cycles are nearly 100% allowing the estimation of a maximum energy density of as high as 240 wh/kg. The Coulombic efficiency showed no marked dependency upon the number of cycles below the 1000 th cycle in repetitive chargedischarge tests. The electrolyte dependence of the battery performance is also investigated.
A Photodiode Array Sensor with Digital Autolevel Setting for Detecting a Small Moving Mark in a Wide Area
Authors: Kusui Shoji , Nagai Tetsuo
Published: February 2005

In order to detect a small moving mark such as a thin edge mark of a rotating disc, a highly sensitive photodiode array sensor is developed. The sensor is composed of an infrared light-emitting diode array and a receiving diode array. As the output signal of the sensor is very small due to slight changes of the light, the detecting slice level of the output signal must be very stable. For this purpose, the slice level is automatically set between the peak and bottom of the output signal by using the digital-to-analogue converter (DAC). Furthermore, the emitted light is chopped and modulated with a high frequency by switching the current of the emitting diode on/off and the output signal of the receiving diode is demodulated for the purpose of preventing the influence of outside light interference. The developed sensor has no focusing lens system and does not demand precise positioning of the sensor. These are great merits compared with conventional sensors.
S2Br2, S2Cl2, S2F2: A New Line of Halogen-Containing Gases for Low-Pressure Plasma Etching Processes
Authors: Pelletier J. , Arnal Y. , Pons M. , Inard A.
Published: February 2005

A methodology for choosing gases able to deliver high concentrations of reactive atoms in low-pressure plasmas is worked out. Application of the resulting criteria reveals that sulfur monohalides S2F2, S2Cl2 and S2Br2 are likely candidates for low-pressure halogen-based plasma etching. The experimental study of plasma etching of Si with S2Cl2 provides confirmation of the merits of this choice. Passivation of the lateral walls by sulfur is also shown not to occur while a high quality of etched surfaces is observed.
Relationship between the Integrated Intensity of the Power Spectrum of Scattered Light and Tissue Blood Volume by the Dynamic Light Scattering Method
Authors: Kashima Susumu , Nishihara Minoru , Takemoto Yoshihiro , Osawa Toshihiko
Published: February 2005

The laser scattering characteristics from tissue microvasculature have been made clear by means of theoretical and experimental approaches. Our results show that the integrated intensity of the power spectrum correlates linearly with the volume of red blood cells in a given tissue provided the average collision number (m̄) between photons and moving red blood cells is less than unity. Also, the integrated intensity of the power spectrum is proportional to tissue blood volume if the density of red blood cells in blood (hematocrit) is constant.
The Melt Threshold of Silicon Irradiated by a Multi-Mode Argon Laser Beam
Authors: Willems G. J. , Maes H. E.
Published: February 2005

The laser beam of an Ar+-laser used for the laser recrystallization of silicon-on-insulator material in a three-dimensional integration process can contain large contributions from higher transversal electro-magnetic (TEM) laser modes of which the doughnut shaped TEM01*
-mode is by far the most important one. An analytical expression is derived for the surface temperature of a bulk silicon wafer irradiated by a pseudo-stationary mixed-mode TEM00-TEM01*
laser spot. The melt threshold of the irradiated wafer is determined as a function of the TEM01*
-mode contribution and as a function of the ratio of the laser power absorptance in the liquid to the laser power absorptance in the solid material. The influence of the TEM01*
-mode contribution on the size of the mixed solid-liquid `slush'-zone is studied quantitatively.
Transient Photoconductivity from the Steady State in Undoped Amorphous Silicon
Authors: Mendoza Doroteo
Published: February 2005

In this study, experimental results of transient photoconductivity decay from the steady state in undoped amorphous silicon are presented. The results are explained within the framework of a theory of multiple trapping. It is found that the occupation function of electrons into the gap behaves as a quasi-Fermi distribution whose quasi-Fermi level moves from its steady-state position to the middle of the gap as time progresses. The rate equation for the free carrier density is numerically solved and compared with the experimental results. A good fit is obtained if one assumes the existence of a peak in the density of states.
On the Determination of the Specific Contact Resistance of Alloyed Contacts to n-GaAs
Authors: Rabinzohn Patrick , Kobayashi Masayoshi , Goto Shigeo , Kawata Masahiko , Usagawa Toshiyuki
Published: February 2005

The popular distributed model for metal-semiconductor ohmic contacts is extended to take into account the nonplanar nature of alloyed contacts. AuGe/Ni ohmic contacts are fabricated on n-GaAs epitaxial layers (3×1018 cm-3, 160 nm) with an undoped cap layer of varied thickness. Thus the specific contact resistance and the so-called alloyed depth are determined from the measured contact resistances. Typical values are, respectively, 10-7 Ω·cm2 and 250 nm.
Theoretical Analysis of Heavy Doping Effects on AlGaAs/GaAs HBT's
Authors: Saito Koki , Konagai Makoto , Takahashi Kiyoshi
Published: February 2005

The minority electron transport in p-type GaAs with hole concentrations greater than 1020 cm-3 was investigated using the Monte Carlo method. It is found that electron-hole and the plasmon scatterings play a dominant role in heavily doped p-type GaAs. The estimated electron mobility and diffusion length are in good agreement with the experimentally obtained values. Based on the above, the static and high-frequency characteristics of AlGaAs/GaAs HBT's were analyzed. The band gap narrowing and the Auger recombination are found to induce substantial effects on the current gain. The maximum frequency of oscillation of 440 GHz and the propagation delay time of 1.5 ps/gate are predicted for the base doping of 1×1021 cm-3.
Etching of InP by H3PO4, H2O2 Solutions
Authors: Mouton A. , Sundararaman C. S. , Lafontaine H. , Poulin S. , Currie J. F.
Published: February 2005

This paper deals with the chemical etching of (100) InP using a phosphoric acid and hydrogen peroxide mixture. It is shown that the etching rate is strongly dependent on the relative concentration of the two species; it is maximal for an equivolumic solution, and depending on the dilution it ranges from 70 to 20 Å/min. The activation energy of a non-diluted solution is approximately 14 kcal/mol. The post-etch surface state of the sample analysed by SEM and XPS, shows a very smooth surface for all concentrations, and the formation of a InPO4·xH2O layer. This solution can be used as a very precise etchant in devices processes.
High Coercive Force of Substituted SrFe12-aMaO19 (M=Al, Cr) Ferrite Particles
Authors: Kohmoto Osamu , Tsukada Takeo , Sato Shigeo
Published: February 2005

The effects of the substitution of Al or Cr into Sr-ferrite powder on the Curie temperature (T
c), saturation magnetization (σs) and coercive force (H
c) were studied for SrFe12-a
M
a
O19 (M=Al, Cr; a=3, 4, 5). With increasing substitution content, both T
c and σs decrease, while H
c increases drastically. We obtained a high H
c of 13.0kOe for SrO·5.8Fe7/6Al5/6O3.
Single-Shot Picosecond Optical Pulse Waveform Measurements Based on a Spatial Sampling System
Authors: Endo Michiyuki
Published: February 2005

Single-shot picosecond optical pulse waveform measurement has been investigated by an electrooptic sampling technique. A spatial optical gate driven by an ultrafast photoconductive switch is employed as an optoelectronic sampler. Discrete sampled signals are coupled into an optical fiber array consisting of fibers of different lengths to control the time delay. The output of the optical fiber array is detected by a photodetector and their envelope is displayed on an oscilloscope with an expanded time scale. For measurement of an optical pulse of 100 ps duration, the temporal resolution of the system is estimated to be about 13 ps.
Optical Properties of CdS Microcrystallite-Doped SiO2 Glass Thin Films
Authors: Tanahashi Ichiro , Tsujimura Ayumu , Mitsuyu Tsuneo , Nishino Atsushi
Published: February 2005

The optical properties of SiO2 glass thin films containing CdS microcrystallites have been investigated. The thin films were deposited onto SiO2 and GaAs substrates using an rf-sputtering technique. X-ray photoelectron spectroscopy and X-ray diffraction measurement indicated that the Cd and S atoms were doped as CdS with a hexagonal system in SiO2 glass matrixes. In the optical absorption spectra, the absorption edge of the films with 18.5 at% of CdS clearly exhibited a blue shift by about 0.13 eV in comparison with that of the bulk CdS. In accordance with this result, the photoluminescence spectra of the films exhibited a blue band-edge emission at a higher energy than that of the bulk CdS. The shift to higher energy seems to be a low-dimensional quantum size effect due to confinement of electrons and holes in CdS microcrystallites.
Droplet and Cluster Ion Emission from Ga and In Liquid Metal Ion Sources
Authors: Hornsey Richard , Ishitani Tohru
Published: February 2005

Although several authors have used the emission of droplets from liquid metal ion sources (LMIS) to explain other phenomena such as cluster ion emission, no model has so far been developed to describe the formation of these droplets. In particular, knowledge of the initial charges and sizes of the droplets is needed in order to predict cluster ion voltage deficits. The present paper sets out a simple model whereby droplets are considered to form from the break-off of the tip sphere from the LMIS apical jet. It is shown that this simple description can be used to derive qualitative variations of LMIS mass loss, Ga and In dimer ion voltage deficits and energy spreads (absolute agreement within a factor of about 2 is found) with current.
Influence of Oxygen upon Radiation Durability of SiN X-ray Mask Membranes
Authors: Oizumi Hiroaki , Iijima Shinpei , Mochiji Kozo
Published: February 2005

The radiation durability of a SiN X-ray mask membrane prepared by low pressure chemical vapor deposition (LPCVD) has been investigated. It is shown that the radiation durability of SiN films is marginally affected by their N/Si compositions, crystalline structures or film stress, but is drastically affected by the oxygen concentration in the film. Mask pattern displacement seems to be changed by breaking the Si–O bonds. A SiN membrane with an oxygen concentration below 1% is found to be stable under X-ray irradiation at a dosage of up to 5 kJ/cm2. Consequently, control of the oxygen concentration during the LPCVD process is vital to obtain high durability SiN X-ray masks.
Neutral-Beam-Assisted Etching of SiO2–A Charge-Free Etching Process–
Authors: Mizutani Tatsumi , Yunogami Takashi
Published: February 2005

Highly directional and low-damage dry etching of SiO2 is realized by neutral-beam-assisted etching reactions. In this etching, low-energy neutral beams and neutral radicals are simultaneously supplied to the specimen, and the etching reactions are enhanced by the neutral beam bombardment. Low-energy (500 eV or less) Ar° neutral beams are generated from Ar+ ion beams by charge exchange reactions. Neutral radicals are generated in a microwave plasma of CHF3. The specimen surface is subjected only to these electrically neutral particles by eliminating charged particles with the retarding grids. The neutral-beam-assisted etching enables deep submicron pattern delineation without any serious radiation damage such as dielectric breakdown. It is a promising substitute for the current plasma etching as a future low-damage etching process.
Low-Temperature Deposition of Hydrogen-Free Silicon Oxynitride without Stress by the Remote Plasma Technique
Authors: Fuyuki Takashi , Saitoh Takashi , Matsunami Hiroyuki
Published: February 2005

Hydrogen-free silicon oxynitride was deposited at 300°C through the reaction of Si from a solid source and neutral oxygen and nitrogen species activated in remote ECR plasma. The IR absorption measurement clearly showed that the composition of oxygen and nitrogen in the film was controlled by simply varying the flow ratio of the source gases of O2 and N2. Oxynitride films without internal stress could be realized by adjusting the film composition of oxygen and nitrogen. The deposited film had high resistivity and breakdown field, and the interface state density between the film and Si was in the lower range of 1010 cm-2eV-1, which were sufficient for device application.
In-Situ RHEED Monitoring of Hydrogen Plasma Cleaning on Semiconductor Surfaces
Authors: Kishimoto Akihiro , Suemune Ikuo , Hamaoka Kazuhiko , Koui Tomoaki , Honda Yoshiaki , Yamanishi Masamichi
Published: February 2005

The first trial of in-situ reflection high-energy electron diffraction (RHEED) monitoring of cleaning processes on semiconductor surfaces with hydrogen (H) plasma was performed. The cleaning time on (100) GaAs surfaces decreased for the higher temperature, while that on (100) Si surfaces increased for the higher temperature. This opposite tendency in the temperature dependence was studied with the measured temperature dependence of the etch rate and the in-situ quadrupole mass spectroscopy. The dependence of the Si surface reconstruction on the angle of incidence of the H-plasma beam is also reported for the first time.
Focused Ga Ion Beam Etching of Si in Chlorine Gas
Authors: Komuro Masanori , Watanabe Norikazu , Hiroshima Hiroshi
Published: February 2005

Etch yield (the number of removed atoms per ion) of Si by showered Ga ion-beam-assisted etching with Cl2 has been measured as functions of gas molecule flux impinged on the sample surface and incident ion flux. It is shown that these results are in good agreement with a theoretical model in which a volatile compound of SiCl4 is created proportionally to the coverage of adsorbed chlorine molecules during ion irradiation. The maximum etch yield reaches 47 and 36 Si atoms/ion for 20 and 5 keV Ga ion, which are nearly proportional to the energy transferred from the incident ion to a lattice system of Si. This etching model is extended to the case of engraving by raster scanning of a focused Ga beam and compared with the experiment. The trends of both results coincide with each other, though the higher ion flux produces a Ga condensation layer which decreases the etch yield.
Local Control of Magnetic Property in Stainless Steel Surface by Ion and Laser Beams
Authors: Sanda Hiroyuki , Takai Mikio , Shigematu Hisao , Chayahara Akiyoshi , Satou Mamoru , Namba Susumu
Published: February 2005

MeV ion and Ar-ion laser beams were impinged onto 304 stainless steel foils to investigate the localized modification of the magnetic property associated with the phase transformation. The intensity of the magnetization was found to increase by MeV Au+ implantation because of the localized martensitic transformation, whereas that of the Ar-ion laser-irradiated areas was found to locally decrease at a laser power of 350 mW and almost extinguish at 550 mW with a beam spot size of 13.2 µm (at 1/e intensity) because of the localized retransformation into austenite. These results indicate that the beam-induced localized phase transformation in stainless steel can be applied to permanent magnetic recording.
Ion Bombardment Enhanced Etching for Bi–Ca–Sr–Cu–O High-Tc Superconducting Thin Films
Authors: Fujiwara Shuji , Yuasa Ryokan , Shikichi Kazuaki , Matsuta Yuh , Nakao Masao , Suzuki Shigeo
Published: February 2005

Ion bombardment enhanced etching (IBEE) has been first applied to Bi–Ca–Sr–Cu–O (BCSCO) high-T
c superconducting thin films. It was found out that the damaged region formed by the ion irradiation with a 200 keV Si++ focused ion beam was selectively dissolved in 1 normal KOH solution. The IBEE process resolves 0.1 µm patterns in the BCSCO films. Other strong alkaline solutions such as NaOH solution were also effective for the selective etching of the BCSCO films, but acid solutions did not give an enhanced etch rate at the irradiated region. The KOH treatment gave no effect on T
c of the BCSCO film. Bridge structures with the width of 1.5 µm were successfully fabricated with little degradation in T
c.
Liquid Phase Epitaxy of Miscible and Immiscible GaInPAs Alloys on (100)-Oriented GaPxAs1-x (x=0, 0.2, 0.4) Substrates
Authors: Ishikawa Masayuki , Onda Tomohiro , Ogasawara Nagaatsu , Ito Ryoichi
Published: February 2005

A comprehensive study on miscible and immiscible GaInPAs LPE layers grown on (100)-oriented GaAs, GaP0.2As0.8 and GaP0.4As0.6 substrates is presented, including the studies by photoluminescence, X-ray diffraction, cathodoluminescence, Auger electron spectroscopy and transmission electron microscopy. Using three types of substrates with different lattice constants, we have obtained some new insights into the miscibility gap of GaInPAs alloys. It has been demonstrated that GaInPAs LPE layers inside the miscibility gap exhibit composition modulations and show peculiarities in luminescent spectra and X-ray rocking curves, the degree of which varies with layer thickness.
Doping Characteristics of Gas-Source MBE-Grown n-AlxGa1-xAs (x=0-0.28) Doped Using Disilane
Authors: Fujii Toshio , Sandhu Adarsh , Ando Hideyasu , Kataoka Yuji , Ishikawa Hideaki
Published: February 2005

Si doping using uncracked disilane (Si2H6) in gas-source molecular beam epitaxy of n-Al
x
Ga1-x
As (x=0-0.28) using triethyl gallium, triethyl aluminum, and arsine was studied in a carrier concentration from 5 × 1017 to 2 × 1018 cm-3. We found that (1) the Si atomic concentration of AlGaAs is proportional to the Si2H6 flow rate, and decreases with increasing Al content at a constant Si2H6 flow rate, and (2) the carrier concentration of AlGaAs shows a square-root dependence on the Si atomic concentration incorporated.
Residual Interface Traps at Bird's Beaks of Field Oxide Layers
Authors: Ando Toshio , Watanabe Kikuo
Published: February 2005

The interface trap density (D
it) of field oxide films is determined from the subthreshold characteristics of parasitic field effect transistors. A D
it of 8×1014 m-2eV-1 persists in the bird's beak regions of local oxidation of silicon (LOCOS) structure after annealing at 723 K in a H2 ambient. This value is almost ten times larger than that observed for a SiO2/Si interface grown on a (100) Si plane.
Comparison of Luminescence from InP Processed by Reactive Ion Beam Etching
Authors: Tadokoro Takashi , Koyama Fumio , Iga Kenichi
Published: February 2005

To obtain a low damage etching condition and to eliminate the damage to InP induced by reactive ion beam etching (RIBE), we compared photoluminescence intensities of etched samples. We also compared electroluminescence of a buried heterostructure laser fabricated using RIBE with stripe lasers. The obtained suitable condition is as follows: the substrate temperature is 150∼175°C; the ion extraction voltage is 300 V; and gas pressure is 1.2×10-3 Torr.
Monitoring Sintering / Densification and Crystallization / Grain-Growth in Tl-Based High Temperature Superconductors by Electrical Conductivity Measurements
Authors: Ratto Joseph J. , Porter John R. , Housley Robert M. , Morgan Peter E. D.
Published: February 2005

An “in situ” electrical resistance method has been used to monitor sintering to best achieve a high percentage of Tl-2223 structure. By this means, the sequential formation of syntactic intergrowths, 2201, 2212 and 2223 structures, was followed as a function of temperature, time, seeding and gaseous atmosphere. At 895°C, slight melting assists the formation of ∼95% pure 2223; the presence of carbonate is probably deleterious.
Decomposition Temperature of Fatty Acid Metal Salts Used as the Constituent Molecules of Molecular Cognizance Thin Solid Films
Authors: Ushikusa Toshiaki
Published: February 2005

The weight loss behaviour and decomposition temperature of calcium, copper, cadmium and barium salts of C16, C18 and C18:1 were studied by thermogravimetry. Initial temperatures of weight loss for metal salts of C16 and C18 in both air and nitrogen flows decreased in the order of Ba ≧ Cd > Ca > Cu. That of C18:1 indicated in the order of Cd > Ba > Ca > Cu. After the initiation of the thermal decomposition, the weitht loss proceeded slowly. This, however, proceeded rapidly from a temperature corresponding to about 10% weight loss. The weight loss from initiation to 25% weight loss was considered to be caused by the decomposition of hydrocarbon moiety, the release of fatty acids and the decarbonation of carboxyl group accompanied by the formation of ketones.
Preparation of BaTiO3 and SrTiO3 Polycrystalline Thin Films on Flexible Polymer Film Substrate by Hydrothermal Method
Authors: Ishizawa Nobuo , Banno Hidekuni , Hayashi Motoo , Yoo Seung Eul , Yoshimura Masahiro
Published: February 2005

Well-crystallized polycrystalline thin films of cubic barium titanate, BaTiO3, and strontium titanate, SrTiO3, have been prepared on the Ti-deposited flexible polymer film of polyphenylen sulfide in Ba(OH)2 and Sr(OH)2 aqueous solutions at temperatures between 120 and 180°C under saturated vapor pressures. The films were dense and lustrous like a mirror. The thicknesses of the films were in the range of 50-250 nm for the hydrothermal treatment time of 1-3 h at those temperatures. The grains were generally uniform and their typical average size for the film formed at 150°C for 1 h in 3N-Ba(OH)2 was approximately 50 nm.
Nitride and Oxide Formation on Pure Metals by Pulse Laser Irradiation
Authors: Nishitani Shigeto R. , Yamaoka Hiroto , Yamaguchi Masaharu
Published: February 2005

Pure metals (Al, Fe, Nb, Ni, Ti, W, and Zr) have been irradiated in air and N
2 gas using a high-power pulse laser, and surface products, nitrides and/or oxides, have been identified by X-ray diffractometry. Which of the nitrides and oxides are formed on the irradiated surface of these metals mainly depends on the boiling point of the metals. The mechanisms of the formation of nitrides and oxides on the surface of metals irradiated by a high-power pulse laser have been proposed.
ArF Excimer Laser Projection Lithography Using Partially Achromatized Lens System
Authors: Ozaki Yoshiharu , Kawai Yoshio , Yoshikawa Akira
Published: February 2005

To study the feasibility of ArF excimer laser lithography, four prototype projection lenses have been designed-a monochromatic lens, an achromatic lens with separate elements, an achromatic lens including cemented elements, and a partially achromatized lens. From the viewpoint of the current technology limit of bandwidth narrowing of ArF excimer laser and accuracy of optical surface fabrication, the partially achromatized lens is found to offer the best solution. 0.18-µm resolution is confirmed using the fabricated prototype lens combined with the 10-pm bandwidth laser and Ag/Se-Ge inorganic resist. Quarter-micron lines-and-spaces pattern is obtained using a tri-layer resist system.
A Chromatic Aberration-Free Heterodyne Alignment for Optical Lithography
Authors: Higashiki Tatsuhiko , Tojo Toru , Tabata Mitsuo , Nishizaka Takeshi , Matsumoto Mitsuo , Sameda Yoshito
Published: February 2005

This paper describes the principle of a new alignment method (SMART) and alignment optics using an optical-heterodyne technique. This SMART dose not need to correct chromatic aberration. Therefore, it dose not require any mechanism, such as mirrors, a prism or a lens system to correct chromatic aberration for the projection lens. A pair of one-dimensional gratings for the mask mark and a checker grating for the wafer mark were used in SMART optics. The relation displacement between the mask and the wafer can be directly detected by measuring the phase difference of the heterodyne beat signals. The experimental result for the phase difference was similar to the calculation result. An alignment signal variation of less than 10 nm was obtained.
Dynamic Thermal Distortions in an X-ray Mask Membrane During Pulsed X-Ray Exposure
Authors: Chiba Akira , Okada Koichi
Published: February 2005

The dynamic thermal distortion for an X-ray mask membrane has been numerically studied with special reference to the effect of elastic waves on its distortion behavior during pulsed X-ray exposure. A partial differential equation governing the dynamic behavior is derived by combining the theory of plane stress and the principle of Hamilton. The calculations based on an implicit finite difference method are performed for a SiN membrane under a 1-bar helium gas environment. Thermal displacement caused by a pulsed X-ray extends in the form of an elastic wave from a terminated rim toward a center. Critical pulse duration is offered in which the displacement in an exposure field does not occur during pulsed X-ray exposure. The peak displacement takes place with a time lag after a pulse exposure.
Update on the Compact Synchrotron X-Ray Source Helios
Authors: Wilson M. N. , Smith A. I. C. , Kempson V. C. , Purvis A. L. , Anderson R. J. , Townsend M. C. , Jorden A. R. , Andrews D. E. , Suller V. P. , Poole M. W.
Published: February 2005

Helios is a compact superconducting Synchrotron X-ray source designed specifically for lithography. It will produce a total X-ray power of 8.2 kW when the design stored beam of 200 mA is achieved. The first phase of commissioning has just been completed in less than 2 months. A stored beam of 305 mA has been accumulated at the injection energy of 200 MeV and 55 mA has been accelerated to the full energy of 700 MeV.
Highly Selective AlSiCu Etching Using BBr3 Mixed-Gas Plasma
Authors: Yoneda Masahiro , Sawai Hisaharu , Fujiwara Nobuo , Nishioka Kyusaku , Abe Haruhiko
Published: February 2005

The effect of selectivity to photo resists when exposed to gas plasma containing Br is studied in AlSiCu etching. The magnetron enhancement reactive ion etching reaction of AlSiCu employs a BBr3/Cl2 gas mixture in comparison with the conventional Cl-containing gas process of SiCl4/Cl2. Selectivity to photo resists increases with increase in the magnetic field when the BBr3/Cl2 process is employed, but not when the SiCl4/Cl2 process is employed. Further, selectivity to photo resists peaks at the concentration of 10% to 20% BBr3. The mechanism behind the highly selective etching is the production of a C-Br compound on the photo resist during AlSiCu etching. This C-Br compound strongly protects the surface of the photo resist. This deposit on the film restrains the etching rate of the photo resist, and high selectivity to the photo resist is obtained by using the gas process containing Br.
Fundamental Characteristics of Capillary-Type Cluster Ion Source and Its Application for Selective Deposition of Aluminum Film
Authors: Ogura Mutsuo , Komuro Masanori , Shimizu Keizo
Published: February 2005

Cluster ions of acetone and triisobutylaluminum (TIBA) are generated from an apex of a capillary tube with an innerdiameter of 5 µm and an outerdiameter of 20 µm, based on the atomization of a semiconductive liquid in high electrostatic field. The ion emission has an onset at a threshold voltage of around 2 kV, which is nearly equal to the value calculated from Taylor's argument. The averaged charge-to-mass ratio of these cluster ions is determined to be 4.0-4.7 Coulomb/kg from a time-of-flight method. Spatially selected chemical vapor deposition of aluminum films is realized by the cluster ions of TIBA.
Si LPE Lateral Overgrowth from a Ridge Seed
Authors: Suzuki Yoshiyuki , Nishinaga Tatau
Published: February 2005

A ridge seed is proposed for use in controlling the layer thickness of an epitaxial lateral overgrowth (ELO). An ELO layer was grown from the ridge seed on a Si(111) substrate, and under a certain growth condition, it was found that no growth occurred at all on the seed except on the side wall, which gave the exact same thickness of the ELO layer as that of the seed. By this technique, a 0.23 µm-thick ELO layer was grown from a ridge seed. This result demonstrates that ELO thickness is controllable down to the order of 100 nm by using the present method. The ratio of the lateral growth width to the layer thickness was developed to 82.
High-Quality p-Type µc-Si Films Prepared by the Solid Phase Crystallization Method
Authors: Matsuyama Takao , Taguchi Mikio , Tanaka Makoto , Matsuoka Tsugufumi , Tsuda Shinya , Nakano Shoichi , Kuwano Yukinori
Published: February 2005

A device-quality p-type microcrystalline silicon (µc-Si)film was prepared using a new solid phase crystallization (SPC) method from the p-type amorphous silicon (a-Si:H) deposited by plasma-CVD. The obtained properties of high conductivity (σd=2×103 (Ω·cm)-1) and a high optical transmittance in the range of 2.0 eV∼3.0 eV are better as a window material for a-Si solar cells than those of conventional p-type µc-Si:H and a-SiC:H.
Effect of Channel Implantation on the Device Performance of Low Temperature Processed Polycrystalline Silicon Thin Film Transistors
Authors: Ono Kikuo , Oikawa Saburou , Konishi Nobutake , Miyata Kenji
Published: February 2005

The characteristics of polycrystalline silicon thin film transistors (TFTs) were experimentally investigated. Boron ions were implanted into the silicon films deposited by LPCVD, and then npn-type TFTs were fabricated on glass substrates using a low-temperature process of below 600°C. The current-voltage curves were measured before and after plasma hydrogenation. The off-state current at a gate voltage of 0 V after the hydrogenation decreased with increasing implantation dose, although the current before the hydrogenation was not affected. It was concluded from comparisions with calculations considering the density of trap states in the silicon energy gap that the dose dependence was attributed to the reduction of defects in the silicon films.
Low-Temperature Synthesis of YBa2Cu3O7-x and YBa2Cu4O8 by Sol-Gel Method
Authors: Murakami Hirohiko , Yaegashi Seiji , Nishino Junya , Shiohara Yuh , Tanaka Shoji
Published: February 2005

The 123 and 124 superconductors were synthesized by sol-gel methods at low temperature. Heat treatment was done below 800°C; neither special equipment nor additives were required. The 123 pellets, which were prepared at 650°C under vacuum condition (0.1 to 1.0 Pa) followed by annealing in flowing oxygen at 750° and 800°C, exhibited zero resistance at 70 and 80 K, respectively. Both the 124 pellets, which were prepared at 780°C in 1 atm oxygen atmosphere followed by either furnace cooling to room temperature or quenching from 780°C to liquid nitrogen temperature, had almost the same transition temperature (T
c(onset)=83-80 K, and T
c(zero)=76–69 K).
Vibration-Induced Intensity Modulation in Multimode Fiber
Authors: Inoue Michiko
Published: February 2005

The mechanism of the linear intensity modulation by external mechanical vibrations on a multimode fiber has been investigated theoretically. The effect of power redistribution among the guided modes which arises from mode-coupling is evaluated for a few-mode fiber. It is shown that linear intensity modulation occurs if the vibration-induced stress of the core lacks axial symmetry. The sensitivity is given by a first order effect in mode-coupling and is significantly enhanced at the resonance condition. This linear effect is a different one from the quadratic effect due to bending loss.
Electrical Conduction of t-Decalin in a Positive Point Electrode
Authors: Arii Kiyomitsu , Kitani Isamu
Published: February 2005

High-mobility positive carrier, so called positive hole, was observed in a dc conduction current measurement for a positive point-plane electrode system in trans-decalin. The mobility value for the hole was arranged between 9.8×10-2 and 2.3×10-1 cm2/Vs, although, in the same liquid, the positive ion mobility was about 7-10×10-4 cm2/Vs.
A Low-Temperature X-Ray Diffraction Study of Structural Phase Transition in La1.86Sr0.14CuO4
Authors: Watanabe Yousuke , Hanaguri Tetsuo , Fukase Tetsuo , Tanaka Isao , Kojima Hironao
Published: February 2005

Using high-quality single crystal samples, the structural phase transition in La1.86Sr0.14CuO4 was investigated by the low-temperature X-ray diffraction method in the range from ambient temperature down to 10 K. The transition temperature from tetragonal to orthorhombic lattice was determined to be 182.5±2.5 K, and neither the monoclinic nor the new tetragonal phase was detected. Since no noticeable change was found in the peak width of (004)t during the phase transition, the shear was estimated to be confined in the direction normal to [001]t. The tilt angle between adjacent domains, determined by (220)t reflection, was of a very small value as 0.013±0.002° at 10 K. This may be related to the observed fourfold symmetry of the upper critical field (H
C2
) in the plane of (001)t.
AsH3 Cracking Characteristics in Gas Source Molecular Beam Epitaxy
Authors: Ohbu Isao , Tezen Yuta , Ataka Saburo , Mozume Teruo
Published: February 2005

A time dependence of AsH3 cracking characteristics in gas source molecular beam epitaxy using metalorganic and hydride gases was found. AsH3 flow for about 1 hour was needed to create a stationary state in the cracking characteristics. During this transitional time, some arsenic, decomposition products of AsH3, was trapped in the cracking cell, and there was a limit to the amount of arsenic that was trapped. The amount of arsenic was limited by the existence of AsH3 in the cracking zone which hindered the trapping of arsenic. The arsenic trapping might be caused by chemical reactions between arsenic and the cracking cell.
Crystal Form of L-α-Alanine-Doped Triglycine Sulfate
Authors: Nakatani Noriyuki
Published: February 2005

Single crystals of ferroelectric TGS were grown from solutions with various concentrations of L-α-alanine, and the variation of crystal form with the alanine content was examined. Some distinctive features dependent on the alanine content were found. The doped crystal grows more rapidly in the +bside of the seed than in the -bside. Therefore, the mirror plane normal to theb-axis of TGS disappears with alanine doping. The degree of asymmetry about the (010) plane increases with increasing alanine content. The form of highly doped crystal clearly shows the polar symmetry 2. The degree of asymmetry has no relevance to the domain structure.
Molecular Motion in Form II Poly(vinylidene Fluoride)
Authors: Nabata Yoshiyuki
Published: February 2005

Relaxation processes and thermal properties of form II poly (vinylidene fluoride) were studied by dielectric, dynamic mechanical, and DSC methods above 200 K. Three mechanical relaxations, αml, αmm, and αmh, were observed above room temperature. The αmlrelaxation was assigned to the dielectric α relaxation. The αmmrelaxation was suggested to be related to the grain-boundary slip process. The αmhrelaxation was assigned to the molecular motion associated with premelting of form II crystals. An endothermic transition, Tr, which was related to the melting of paracrystalline regions existing at lamellar surfaces, was also found.
Hydrogen-Radical-Assisted Chemical Vapor Deposition of SiN Films Using Si(CH3)4 and NH2CH3
Authors: Yasui Kanji , Nasu Masaaki , Kaneda Shigeo
Published: February 2005

Hydrogen radicals generated by microwave were employed in the growth of SiN films using tetramethylsilane and monomethylamine as source gases. Under appropriate experimental conditions, SiN film containing almost stoichiometrical nitrogen and small residual contents of carbon and oxygen was obtained.
Measurement of Plasma Flow of Mixture of Metal Vapor and Nitrogen in Shock Wave Deposition
Authors: Ezumi Hiromichi , Osono Hiroto , Kuwahara Kaizo
Published: February 2005

The plasma flow of a mixture of metal vapor and nitrogen in shock wave deposition has been investigated by means of an image converter camera and a Mach-Zehnder interferometer at the shock velocity of υ=4.9∼6.0 km/s with the initial pressure of P
1=0.1∼2.0 Torr. The separation of the shock front between N2 and Mo was observed at P
1=0.1 Torr, but not at P
1≧1.0 Torr. The density of nitrogen molecules behind the shock front was measured to be 3.47×1017 cm-3 for P
1=1.0 Torr and υ=4.9 km/s. The deposited films of MoN and TiN were found to be composed of fine-grained polycrystals with FCC structure, and their lattice constant was estimated to be 0.422 nm and 0.426 nm, respectively.
Theoretical Model and Numerical Simulation of Two-Longitudinal-Mode Oscillation in an Injection-Locked TEA CO2 Laser
Authors: Sasaki Koichi , Ohno Hirotaka , Tsukishima Takashige
Published: February 2005

Injection locking of a TEA CO2 laser is studied theoretically from the point of view of analyzing its two-longitudinal-mode oscillation (TLMO) observed experimentally. A phenomenological theoretical model and a new method of numerical calculation are developed to simulate TLMO locked with a monochromatic injection field. In the proposed theoretical model, injected radiation is allowed to couple with two neighboring longitudinal modes with assumed coupling coefficients. By making use of the proposed algorithm, rapid temporal variation of population densities and cavity fields can be calculated numerically, maintaining the correct phase relation. The simulation results show good agreement with experimental results and the power-modulated output of the TEA CO2 laser is obtained theoretically.
Thermodynamics of Development Process of Positive Resists in Binary Mixed Developer
Authors: Watanabe Hisashi , Todokoro Yoshihiro , Inoue Morio
Published: February 2005

The sensitivity of positive e-beam resists depends strongly on the development condition. We have found that a small amount of water in an organic developer enhances the resist dissolution rate resulting in development instability. The addition of polar solvents to a developer causes a large increase of the dissolution rate. The reason for this enhancement of the dissolution rate is explained by thermodynamic compatibility between the resist and the developer. It is shown that thermodynamic consideration of the development process is very useful to comprehend the dissolution characteristics of positive resists in binary mixed developers.
Characterization of Lattice Sites and Compensation Mechanism in Heavily Si-Doped GaAs with Laser Raman Spectroscopy
Authors: Uematsu Masashi , Maezawa Koichi
Published: February 2005

Lattice sites in heavily Si-doped GaAs have been investigated by means of Raman spectroscopy. Localized vibrational modes (LVM) due to SiGa-VGa complex and SiGa were observed as well as SiGa-SiAs pair and SiAs modes. Raman scattering efficiency was obtained from the spectrum area of each mode. The concentrations of these four Si-related sites were estimated, and the results indicate that the carrier compensation mechanism after annealing is dominated by SiGa-VGa acceptors and/or SiGa-SiAs neutral pairs depending on the annealing conditions. The compensation mechanism of the as-grown sample and Si-implanted GaAs has also been studied.
Electroluminescence in CaO:Eu Thin Film
Authors: Abe Yoshio , Onisawa Ken-ichi , Ono Yoshimasa A. , Hanazono Masanobu
Published: February 2005

A CaO:Eu thin film electroluminescent (EL) cell was fabricated and its EL characteristics were studied. A sharp emission at 595 nm, a weak emission around 620 nm and a broad-band emission around 720 nm were observed. The emissions at 595 nm and 620 nm were assigned to the 5D0→7F1 and 5D0→7F2 transitions in Eu3+ ions, respectively. The emission around 720 nm could be the 4f65d→4f7 transition in Eu2+ ions taking into consideration the fact that a smaller anion-cation distance in CaO would decrease the Eu2+ emission energy in calcium chalcogenide host lattices.
Blue Coloration of Evaporated Films of Sodium Chloride by Electron Irradiation
Authors: Aso Jun-ichi , Baba Mamoru , Ikeda Toshio
Published: February 2005

Coloration of evaporated films of NaCl has been studied by electron irradiation at various temperatures from 20 to 300°C. As for single crystals of NaCl, blue coloration has been obtained above about 80°C and ascribed to the formation of X or colloidal centers. In the earlier stage of coloration, the growth rate of coloration in the films is several times larger than that in the crystals. The extinction bands in the blue range are narrower in the films than those in the crystals. These results can be explained by assuming that the many more crystal imperfections in the polycrystalline NaCl films offer a large number of nucleation sites for F-center aggregation. Thermal and optical stabilities of the extinction bands enable us to use them for the highly persistent display or memory of an image.
AC Measurements on Silver Photodoping into Ge30S70 Glass
Authors: Doi Akira , Sakai Hirokazu , Yamamoto Mamoru , Kawaguchi Takeshi , Maruno Shigeo
Published: February 2005

The process of photodoping of Ag into Ge30S70 glass was studied with ac measurements at room temperature in vacuo. It was suggested that the dominant charge carriers in the photodoped phase were silver ions and that, although their distribution was steplike, as already reported, it was not so abrupt at the step front. The photodoping process was explained in terms of ionic conduction caused by photoenhanced internal electric field.
Nanostructural-Property Relations in Complex Lead Perovskites
Authors: Randall C. A. , Bhalla A. S.
Published: February 2005

From transmission electron microscopy studies on several complex lead perovskite compounds Pb(B'B'')O3, and their solid solutions a classification can be obtained based on B-cation order. This classification divides the complex lead perovskites into three subgroups; random occupation or disordered, nanoscale or short coherent long-range order and long coherent long-range order of B-site cations. A correlation between the nanoscale B-site order and relaxor on glassy ferroelectric behavior is found in these lead perovskites. An hypothesis is suggested which relates 0-3 polar connectivity to 0-3 order-disorder connectivity. This hypothesis is discussed with relation to present theories [G. A. Smolenskii: J. Phys. Soc. Jpn. (1970) Suppl., p. 26, L. E. Cross: Ferroelectrics 76 (1987) 241, T. L. Renieke and K. L. Ngai: Solid State Commun. 18 (1973) 1543] and reported experimental results of the perovskite relaxor ferroelectrics.
Deformation of the Helical Structure during the Unwinding and Winding Process of Ferroelectric Liquid Crystals
Authors: Nawa Nobuhiko
Published: February 2005

The effect of magnetic field on the molecular alignment of ferroelectric liquid crystals is observed on the cooling process from an isotropic phase to a chiral smectic C phase. In a sample having phase sequences I-N*-SA-SC
*, the monodomain is formed under the magnetic field. The texture change relating to the deformation of the helical structure is investigated in the monodomain. When a d.c. voltage is applied in the SC
* phase, the focal conics appear at a low voltage range below the threshold for unwinding of the helix. While the voltage is decreased after the unwinding, the helical structure begins to form from the focal conics. The electrooptic effect induced by the deformation of the helical structure depends on the molecular alignment in the SC
* phase.
Dynamic Critical Behavior of a Physical Gel
Authors: Ikeda Takahiro , Tokita Masayuki , Tsutsumi Akihiro , Hikichi Kunio
Published: February 2005

The dynamic mechanical property of gelatin gel was studied in the vicinity of the sol-gel transition point. It was found that the storage and the loss shear modulus G' and G'' exhibit a power-law dependence on the frequency f, G'∝G''∝f

n
, at the sol-gel transition point. The value of the rheological exponent n obtained here was 0.58±0.05.
Characterization of Amorphous Carbon Films Prepared by Photo-Enhanced Chemical Vapor Deposition at Low Temperatures
Authors: Yasuda Tetsuji , Komiyama Hiroshi
Published: February 2005

Amorphous C films were prepared under radical-controlled ambience using a photo-enhanced chemical vapor deposition system proposed by the authors and were characterized by various techniques. The deposition system consisted of a CH4/Cl2 mixture and a super-high-pressure Hg lamp, and the deposition temperature ranged from 343 to 573 K. The samples were soft, and their Cl/C and H/C ratios were 0.035-0.09 and below 0.03, respectively. The elemental compositions were examined, referring to the concentrations of gas-phase radicals estimated previously. The sample prepared at 343 K showed a resistivity as high as 2.5 × 108 Ω·cm and an optical band gap of 1.25 eV, both of which decreased with temperature. The s
p
3/s
p
2 ratio and the degree of ordering of s
p
2-bonded atoms were investigated, using the results of TEM, RHEED, XPS, Raman and IR spectra, and optical-gap measurement.
Non Faceted Surfaces of Cd Crystals Grown from Cd-Pb Droplets by the VLS Method
Authors: Yumoto Hisami , Watanabe Tsuneo , Kishi Kiyoshi , Igata Naohiro
Published: February 2005

Polyhedral Cd crystals having either 14 or 20 faces were grown from Cd-Pb droplets by the VLS (vapor-liquid-solid) method. Their surfaces were always curved over the growth temperature range, and the faceted-to-non faceted transition did not occur in this system. This transition, however, occurred in other system such as Cd-Bi, Cd-Sn, Zn-Sn and Zn-Bi. The quasi-dangling bond model [H. Yumoto et al.: J. Cryst. Growth 82 (1987) 459] was able to explain this phenomenon. When the interfacial components of the nearest neighbors of A and B are different from each other in an A-B binary system, quasi-dangling bonds are generated. As there are no quasi-dangling bonds in the Cd-Pb system, a rough surface always has a lower solid-liquid interfacial free energy than that of a smooth surface.
Brillouin Scattering Study of Elastic Anisotropy in an Injection Molded Polycarbonate Solid
Authors: Shirouzu Shigenori , Tagami Sanae , Sakai Akira , Yagi Toshirou
Published: February 2005

Brillouin scattering study of injection molded polycarbonate solids reveals an isotropic and homogeneous elastic property of the sample plate in spite of its optical anisotropy and strong position dependence of the birefringence.
An Automated Simultaneous Recording System for the Pupillary Movement and Unitary Discharge of the Ciliary Nerve in Cats
Authors: Watanabe Takeru , Koike Nobuyuki , Inoue Takamichi , Kondo Yasuyuki , Yanagaki Hidenori , Yasuda Tetsuya
Published: February 2005

A computer-automated measuring system was fabricated for real-time, simultaneous data acquisition of the pupillary movement and efferent discharge of the ciliary nerve in animals. For detection of the pupil size, the system incorporates an infrared television camera synchronized by an Apple II computer. It also has an interface circuit which registers the occurrence of nerve impulses and triggers light and electrical stimulators. All the interfaces with the computer were electrically isolated to improve the resistance to noise. A measurement-oriented program was created to provide menudriven commands such as automated measurement, data storage, and data-file load. Simultaneous recordings in the cat have been obtained and are presented for the first time.