bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-Band Electroluminescent Emission in Organic Electroluminescent Diode with Phthalocyanine Film
Authors: Akihiko Fujii Akihiko Fujii , Masayoshi Yoshida Masayoshi Yoshida , Yutaka Ohmori Yutaka Ohmori , Katsumi Yoshino Katsumi Yoshino 
Published: October 2002

An electroluminescent (EL) diode utilizing metal-free phthalocyanine ( H2Pc) has been fabricated by the vacuum evaporation method. The optical characteristics of the EL diode, such as the spectra of absorption, photocurrent and electroluminescence, have been investigated, and their temperature dependence has been discussed. We have found, for the first time, that the EL spectrum has two discrete peaks at around 480 nm and above 800 nm.
Smooth and Precipitate-Free Surface of in situ Superconducting Bi2Sr2CaCu2Oy Epitaxial Thin Films Grown on LaSrGaO4 Substrate
Authors: Shin-ichi Karimoto Shin-ichi Karimoto , Shugo Kubo Shugo Kubo , Koji Tsuru Koji Tsuru , Minoru Suzuki Minoru Suzuki 
Published: October 2002

We report that LaSrGaO4 substrates are very effective in attaining a smooth and almost precipitate-free surface in in situ grown superconducting Bi2Sr2CaCu2O

y

thin films. These films are grown epitaxially by computer-controlled two-target magnetron sputtering under a high pressure of 0.3–0.5 Torr on LaSrGaO4 (001) substrates heated to 665°C. X-ray diffraction measurements showed no trace of precipitates nor of other phases. AFM, high-resolution SEM and RHEED observation revealed that the film surface is quite smooth and free from precipitates. The surface roughness is no greater than 1.5 nm, half the c-axis lattice constant. The films have a resistivity of as low as 240 µΩ· cm at 300 K and a T
c of 70–80 K.
Transparent Conducting Al-Doped ZnO Thin Films Prepared by Pulsed Laser Deposition
Authors: Akio Suzuki Akio Suzuki , Tatsuhiko Matsushita Tatsuhiko Matsushita , Naoki Wada Naoki Wada , Yoshiaki Sakamoto Yoshiaki Sakamoto , Masahiro Okuda Masahiro Okuda 
Published: October 2002

Thin films of ZnO:Al have been deposited on glass substrates by a pulsed laser deposition technique employing an ArF laser ( λ=193 nm). For all experiments, a repetition rate of 10 Hz, an energy density of 1 J/cm2, and an irradiation time of 20–30 min (12000–18000 shots) were assumed. Optical transmittance of around 90% was observed in the visible region of the spectrum for the 150–200 nm thick film. Resistivities of 1.43×10-4 Ω·cm and 5.62×10-4 Ω·cm were obtained at substrate temperatures of 300°C and room temperature, respectively.
Time-Resolved X-Ray Absorption Spectroscopy for Laser-Ablated Silicon Particles in Xenon Gas
Authors: Tetsuya Makimura Tetsuya Makimura , Tamaki Sakuramoto Tamaki Sakuramoto , Kouichi Murakami Kouichi Murakami 
Published: October 2002

We developed a laboratory-scale in situ apparatus for soft X-ray absorption spectroscopy with a time resolution of 10 ns and a space resolution of 100 µm. Utilizing this spectrometer, we have investigated the dynamics of silicon atoms formed by laser ablation in xenon gas. It was found that 4d-electrons in the xenon atoms are excited through collision with electrons in the laser-generated silicon plasma.
Effect of Nb Doping on Fatigue in Lead Zirconate Titanate
Authors: Kaoru Miura Kaoru Miura , Masahiro Tanaka Masahiro Tanaka 
Published: October 2002

We investigated the effect of Nb doping on fatigue in lead zirconate titanate (PZT), using the discrete variational Xα cluster method. From our calculation results, we conclude that Nb-doped PZT (PZTN) is less susceptible to fatigue than PZT because electrons released from oxygen vacancies occupy the Nb 4d states. This is consistent with our previous calculations; the effect of Nb doping on fatigue in PZT is the same as that of La doping on fatigue in PZT.
Magnetotunnelling and Photoluminescence Spectroscopy of Self-Assembled InAs Quantum Dots
Authors: E. Itskevich Igor , Henini Thomas Ihn , Carmona Humberto de Andrade , Eaves Laurence , Main Peter Clifford , Maude Duncan Kennedy , Portal Jean-Claude 
Published: October 2002

Self-assembled InAs quantum dots (QDs) in AlAs and GaAs matrices are investigated by tunnelling and optical spectroscopy. Tunnelling through an individual QD in the AlAs barrier of a n-i-n single-barrier device is used to probe the properties of both the emitter two-dimensional electron gas (2DEG) and the QD. The Landau fan of the 2DEG is mapped at magnetic field parallel to the tunnelling current, B\VertI, as well as the spin splitting in the QD at B⊥I. An electron g-factor in the QD is determined as ∣g∣=1.2±0.5. In the photoluminescence spectrum of InAs QDs in B up to 23 T, a strong anisotropy in the diamagnetic shift is found. The spatial extent of the carrier wave function in the dot is estimated as 60 Å. Under hydrostatic pressure up to 8 kbar, the pressure coefficient for the dot emission line is (9.1±0.2) meV/kbar, about 20% smaller than for the Γ-point bandgap in bulk GaAs.
Highly Field Sensitive (150 Oe) Quadri-Valued Magnetooptical Media for High-Speed Overwriting
Authors: Takao Hiroki , Shimazaki Katsusuke , Ohta Norio , Yoshihiro Masafumi , Nobuyuki Nagai Nobuyuki Nagai , Susumu Imai Susumu Imai 
Published: October 2002

For high-density and high-speed magnetooptical (MO) recording, the use of magnetic multi-valued (MMV) MO media has been proposed. [rf:1] A quadri-valued recording has been achieved using this media and a field modulation recording method. For practical use of this media, it is important to reduce the critical magnetic field to minimize the applied field for realizing the quadri-valued recording. We have achieved reduction of the critical magnetic field down to 150 Oe using a new coupled film, TbFeCo/GdTbFeCo.
Magnetic Properties and Structure of Nd–(Fe, B) Nanocomposite Alloys with Fixed Fe/B Ratios at 4–14
Authors: Fang Jau-Shiung , Hsieh Ming-Fu , Chen Shi-Kun , Tsung-Shune Chin Tsung-Shune Chin 
Published: October 2002

Magnetic properties and nanostructure of pseudobinary Nd–(Fe, B) alloys with fixed Fe/B ratios of 4, 6, 8, 10, 14, respectively and Nd=3 to 11 at.%, prepared by melt-spinning and rapid thermal annealing (RTA), were investigated. Magnetic properties were found to depend on nanostructure, particularly the size and size distribution of hard and soft phases, which were in turn determined by Nd contents and Fe/B ratios together with RTA processing. The maximum energy products, (BH)max
, of the optimally RTA treated 11 at.%Nd flakes with Fe/B=10 and 14 are 19 MGOe and 18.8 MGOe, respectively. However, the remanence decreases with increasing Nd contents due to the decreasing amount of Fe nanocrystal. The Fe/B=6 alloys with Nd<6 at.% showed very low intrinsic coercivity (iHc) and (BH)max
, which were attributed mainly to impurity phases, typically Nd2Fe23B3 and Nd1.1Fe4B4. The reversible and irreversible magnetization behaviors were also studied in order to quantify the exchange coupling interaction between hard and soft phases of alloys. The variation in nucleation field at the same Fe/B ratio of 14 was found to depend on volume fraction of hard phase formation as well as the size distribution of the two phases.
Compact Diode-Pumped Cr3+:LiSrAlF 6 Femtosecond Laser
Authors: Shin-ichiro Aoshima Shin-ichiro Aoshima , Haruyasu Itoh Haruyasu Itoh , Yutaka Tsuchiya Yutaka Tsuchiya 
Published: October 2002

A novel geometry for dispersion compensation in femtosecond lasers without specific cut of optical parts in a flat/Brewster angle is demonstrated for the purpose of a compact diode-pumped Cr:LiSAF femtosecond pulse laser. In the geometry, the laser medium lies between the dispersion-compensation prism pair. This approach enables the laser to operate at variable repetition rates from 163 to 235 MHz keeping the pulse width less than 90 fs, which is the shortest pulse to our knowledge, achieved in an all-solid-state Kerr-lens mode-locked laser operating at a repetition rate of greater than 200 MHz.
Measurement of Einstein's A Coefficient of the 296.7 nm Transition Line of the Carbon Atom
Authors: Haruhiko Ito Haruhiko Ito , Masafumi Ito Masafumi Ito , Masaru Hori Masaru Hori , Akihiro Kono Akihiro Kono , Takashi Takeo Takashi Takeo , Terumasa Kato Terumasa Kato , Toshio Goto Toshio Goto 
Published: October 2002

We measured Einstein's A coefficient of the transition line of the C atom at 296.7 nm (2s2p
3
5S2 - 2s
22p
2
3P2), which is useful for the absorption spectrocopic measurement of C atom density in processing plasmas. Einstein's A coefficient was evaluated from the emission decay rate of the 296.7 nm line in an electron cyclotron plasma employing CO gas. The obtained value of 3.9×104 s-1 is almost 2000 times as large as the reported theoretical A coefficient [G. H. Garstang: The Observatory 82 (1962) 50].
Absolute Fluorine Atom Densities in Fluorocarbon High-Density Plasmas Measured by Appearance Mass Spectrometry
Authors: Keiji Nakamura Keiji Nakamura , Kazunori Segi Kazunori Segi , Hideo Sugai Hideo Sugai 
Published: October 2002

We report absolute fluorine atom (F) density measurements based on appearance mass spectrometry (AMS). A liquid nitrogen cold trap installed in a mass spectrometer dramatically reduces background noise at m/e=19 (F+), enabling reliable AMS measurement of F density. The F density reaches ∼1019 m-3 in high-density inductively coupled plasmas in 100 % CF4 or C4F8 while addition of 50 % hydrogen decreases the F density by one order of magnitude. A conventional actinometry technique results in a factor of ∼4 greater reduction of F density in comparison with the AMS result. High etch selectivity of SiO2 to Si is achieved for the radical density ratio CFxF larger than 25 (x=1–3).
Relation between ESR and Hydrogen in Magnetron-Sputtered a-Ge:H
Authors: Hoonkee MIN Hoonkee MIN , Shoichi UEDA Shoichi UEDA , Minoru KUMEDA Minoru KUMEDA , Tatsuo SHIMIZU Tatsuo SHIMIZU 
Published: October 2002

On the basis of ESR measurements, the g-value between 2.019 and 2.023 and peak-to-peak linewidth (ΔH
pp) between 35 and 50 G have been reported in a-Ge and a-Ge:H. However, we observed a smaller g-value of 2.014 in hydrogen-rich a-Ge:H. Such a small g-value in hydrogen-rich a-Ge:H is thought to arise from a different local structure around the Ge dangling bond than that in previously reported samples. In order to clarify the reason for the small g-value in hydrogen-rich a-Ge:H, we investigated the change in the g-value under various deposition conditions and with increasing annealing temperature.
Dependence of Frequency and Pressure on Electron Energy Distribution Functions in Low Pressure Plasma
Authors: Haruaki Akashi Haruaki Akashi , Seiji Samukawa Seiji Samukawa , Nobuaki Takahashi Nobuaki Takahashi , Tai Sasaki Tai Sasaki 
Published: October 2002

The electron energy distribution functions (EEDF), ionization frequency R
i and mean electron energy ε in a low pressure high frequency (13.56 MHz–1 GHz) discharge in Ar gas have been examined using Monte Carlo method. The dependence of driving frequency on the EEDF, R
i and ε is calculated. As the frequency increases, the lower energy electrons increase significantly because they can not follow the applied high frequency electric field. Then, R
i and ε decrease with increasing frequency. The dependence of pressure on EEDF, R
i and ε under applied frequencies of UHF (500 MHz) and RF (13.56 MHz) is also investigated for actual etching pressures. The EEDF, R
i and ε in the UHF plasma do not depend on the pressure, whereas those in the RF plasma are strongly influenced by the pressure. It is considered that the driving frequency (UHF) is higher than the electron collision frequency in the plasma.
The Concentration Dependence of the Hole Mobility of a Hydrazone Doped Polymer
Authors: Borsenberger P. M. , Magin E. H. , J. A. Sinicropi J. A. Sinicropi , L.-B. Lin L.-B. Lin 
Published: October 2002

Hole mobilities of 4-diethylaminobenzaldehyde diphenylhydrazone (HDZ-F) doped poly(styrene) have been measured over a wide concentration range. The results have been described by a formalism based on disorder. The formalism is premised on the argument that charge transport occurs by hopping through a manifold of localized states that are distributed in energy and distance. The key parameter of the formalism is σ, the energy with of the hopping site manifold. For HDZ-F doped PS, σ is concentration-dependent. The maximum value is 0.121 eV and occurs at approximately 15% HDZ-F. The width decreases sharply for concentrations above and below. The concentration dependence is described by a model of dipolr disorder. The model is based on the assumption that the total widths are comprised of a dipolar component and a van der Waals component. The interpretation of the experimental results leads to the conclusion that the concentration dependence of the total width is largely determined by the van der Waals component.
Electron Affinity Difference in CdS/Si Solar Cells
Authors: Kuhaimi Siham A. Al 
Published: October 2002

The electron affinity difference ΔE
c=χ1-χ2, in CdS/Si solar cells fabricated
by four different processes is measured from observations of the variations of open
circuit voltage with temperature. For CdS/Si cells, the values of ΔE
c lie between 0.43
and 0.48 eV and are found to be independent of the process of cell fabrication. The
use of CdZnS in place of CdS decreases the value of ΔE
c to 0.3 eV. The method used
for the measurement of ΔE
c is very simple. The values of the saturation current I
0 for
different types of cells are estimated from the slopes of q
V
oc versus k
T characteristics
and compared with those obtained from ln I versus V curves. The values of I
0 found
for each cell by the two methods are in good agreement.
Thin CoSi2 Formation on SiO2 with Low-Energy Ion Irradiation
Authors: Atsushi Matsushita Atsushi Matsushita , Taizoh Sadoh Taizoh Sadoh , Toshio Tsurushima Toshio Tsurushima 
Published: October 2002

Cobalt silicides were formed by heat treatment and ion irradiation for stacked 7 nm Co and 25 nm Si layers on 20 nm SiO2 films.
Irradiation was performed with 25 keV Ar+ ions to a dose of 5 ×1015 cm-2 at sample temperatures between room temperature and 700°C.
The phase, atomic concentration profiles, and sheet resistance of the silicide layers were investigated as a function of the processing temperature.
X-ray diffraction measurement showed that the phase of CoSi2 was formed by irradiation at temperatures above 300°C, and X-ray photoelectron spectroscopy measurement revealed uniform distributions of Co and Si atoms with the atomic ratio of Co:Si=1:2 for samples irradiated at temperatures above 200°C.
Sheet resistance measurement showed that almost complete di-silicidation occurred by irradiation at 700°C.
It is concluded that the energy deposited by ions contributes to the migration of the species for silicidation at a lower temperature, and Co/Si mixed layers with an atomic ratio of 1:2 are easily obtained by irradiation of the stacked thin films with low-energy ions.
Since the silicide regions formed in the deposited thin films were decomposed during the irradiation at temperatures below 700°C, thermal annealing at 700°C is necessary to obtain completely uniform CoSi2 layers after the irradiation.
Morphology Control of Cu Clusters Formed on H-Si(111) Surface in Solution by Si Potential
Authors: Ken-ichi Hara Ken-ichi Hara , Iwao Ohdomari Iwao Ohdomari 
Published: October 2002

We have controlled the morphology of Cu clusters formed on H-terminated Si(111) surface in solution by controlling Si potential. At a Si potential of -0.70 eV vs SHE, Cu wires of 50 nm width were formed along a ridge composed of dihydride Si atoms at the intersections of steps equivalent to
[11\overline2]. In contrast, no Cu morphology was observed along a
ravine composed of monohydride Si atoms.
Helicity-Modulation Technique Using Diffractive Phase Retarder for Measurements of X-ray Magnetic Circular Dichroism
Authors: Motohiro Suzuki Motohiro Suzuki , Naomi Kawamura Naomi Kawamura , Masaichiro Mizumaki Masaichiro Mizumaki , Akiri Urata Akiri Urata , Hiroshi Maruyama Hiroshi Maruyama , Shunji Goto Shunji Goto , Tetsuya Ishikawa Tetsuya Ishikawa 
Published: October 2002

A diamond X-ray phase retarder has been combined with
a phase-sensitive detection method to improve the accuracy
of X-ray magnetic circular dichroism (XMCD) measurements.
Fluctuation of the absorption coefficient of a magnetized sample
was induced by photon-helicity switching at 40 Hz by flipping the
phase retarder, and directly detected through a lock-in amplifier
referring to the helicity-modulation frequency.
This new technique for XMCD measurements was applied to
the Fe K-edge in pure Fe foil.
XMCD spectra of higher signal-to-noise ratio were obtained in
shorter measuring time.
Possibility of Reduction in Hysteresis Loss Due to Reversible Fluxoid Motion in a Superconducting Bi-2223 Multifilamentary Wire
Authors: Otabe Edmund Soji , Matsuoka Hiroshi , Matsushita Teruo , Fujikami Jun , Ohmatsu Kazuya 
Published: October 2002

The energy loss density was measured and the AC penetration depth, λ0', was estimated from the slope of a minor magnetization curve for a superconducting Bi-2223 multifilamentary tape at various temperatures under the application of a parallel AC magnetic field to the tape. It was found that at high temperatures λ0' was comparable to the filament thickness and the energy loss density was lower than that predicted using a modified Kim's model taking into account the effect of the diamagnetism. This reduction is ascribed to the reversible fluxoid motion inside pinning potential wells. The reduction of the filament thickness to less than 2 µm is recommended for the achievement of the low energy loss density at 77 K.
Preparation of Organic Silica Films with Low Dielectric Constant from the Liquid Phase
Authors: Koh-ichi Usami Koh-ichi Usami , Kazuhito Sumimura Kazuhito Sumimura , Masakiyo Matsumura Masakiyo Matsumura 
Published: October 2002

Silica films with dense methyl-groups were grown from the liquid phase using methyl-triethoxy-silane, aiming at inter-metal-dielectrics applications. The film showed insulating characteristics even under as-deposited conditions. The dielectric constant, low-field resistivity and breakdown field-strength were 4.5, 3×1013 Ω cm and 1 MV/cm, respectively. They were improved to 2.9, more than 5×1014 Ω cm and more than 2 MV/cm, respectively, after 400°C vacuum annealing.
Improved Extinction Ratio in Ultra Short Directional Couplers Using Asymmetric Structures
Authors: Boo-Gyoun Kim Boo-Gyoun Kim , Ali Shakouri Ali Shakouri , Bin Liu Bin Liu , John E. Bowers John E. Bowers 
Published: October 2002

Various means of increasing the extinction ratio in ultra short
directional couplers using slight asymmetry in the coupled waveguide
structure are investigated. It is shown that couplers with 10–200 µm coupling length and with high extinction ratios larger than 30 dB can be achieved. Shorter asymmetric couplers have an extinction
ratio that is more fabrication tolerant.
Test-Wave Measurements of Microwave Absorption Efficiencyin a Planar Surface-Wave Plasma Reactor
Authors: Ivan Ghanashev Ivan Ghanashev , Shin Morita Shin Morita , Naoki \scToyoda Naoki \scToyoda , Masaaki Nagatsu Masaaki Nagatsu , Hideo Sugai Hideo Sugai 
Published: October 2002

A major obstacle for experimental surface-wave (SW) excitation
and propagation studies in SW plasma is the self-consistent
behaviour of the latter, which does not permit continuous
variation of the electron density n
e. In the present
study, we demonstrate how this obstacle can be overcome by an
independent plasma source, in our case, an inductively coupled
plasma (ICP) created by a high-power RF (13.56 MHz) generator.
Through a rectangular waveguide short-circuited at its end by a
movable plunger, we introduced into the ICP a weak (power
less than 20 W) nonionising 2.4 GHz microwave.
This permitted us to highlight important SW excitation and
propagation phenomena. In particular, we confirmed the existence
of the predicted [Jpn. J. Appl. Phys. 36 (1997) 4704]
resonance minima in the n
e dependence of the power
reflection coefficient. The influence of the plunger position
on the chamber matching was studied systematically and four
different coupling aperture geometries were compared.
Chemical Kinetic Modelling of Non-Equilibrium Ar-H2 Thermal Plasmas
Authors: G. Beuthe Thomas , Chang Jen-Shih 
Published: October 2002

A chemical kinetic model has been constructed to predict the gas and electron
temperature dependence of the neutral and ionic species composition in
Ar-H2 mixtures under thermal plasma conditions. The
model includes electron impact, thermal impact, ion-molecule, and recombination
reactions as well as accounting for diffusion. Important metastable and excited
states of species have been accounted for as well as the presence of neutral
molecules, radicals, and atoms, positively and negatively charged atoms and
molecular ions, and electrons. All relevant electron temperature, gas
temperature and pressure terms have been included.
Calculations were performed for electron and gas temperatures between
300 and 15000 K and various pressures.
Under equilibrium and non-equilibrium conditions, Ar, H2, H,
ArH3
+, Ar+, H+, H- and electrons
were found to be the dominant neutral and charged species.
No significant negative ion concentrations are observed.
Microwave Dielectric Properties of Ba4(Nd28/3-yRy)Ti18O54 (R = Eu, Dy, Ho, Er and Yb) Solid Solutions
Authors: Hitoshi Ohsato Hitoshi Ohsato , Junichi Sugino Junichi Sugino , Atsushi Komura Atsushi Komura , Susumu Nishigaki Susumu Nishigaki , Takashi Okuda Takashi Okuda 
Published: October 2002

We have investigated the formation and the microwave dielectric properties of the
Ba4(Nd28/3-y
R
y)Ti18O54 (R = Eu, Dy, Ho, Er and Yb) solid solutions in which R ions are substituted for Nd ions in Ba6-3x
Nd8+2x
Ti18O54 solid solutions with x=2/3.
Based on the change of the volume of the unit cell, it was inferred that Eu, Dy, Ho and Er ions substituted into rhombic A1-sites, but Yb ions did smaller sites such as B-sites and C-sites after substituting A1-sites.
The quality factor (Q·f) improved as the ionic radius of substituted
R ions increased. In the Eu series, the best Q·f value of 10405 GHz was obtained.
The temperature coefficients of the reasonant frequency (τ
f
) in the Dy, Ho and Er series were improved by more than 50%, but the dielectric constant (ε

r
) showed only a nominal change of about 3–4 in the vicinity of 80.
A Study of Loading Effect during Electron-Beam Exposure and Etching Process in Photomask Fabrication
Authors: Choi Ji-Hyeon , Kim Byung-Gook , Jeon Chan-Uk , Cho Sung-Yong , Choi Seong-Woon , Sohn Jung-Min 
Published: October 2002

As the requirements of critical dimension (CD) uniformity on photomasks continue to tighten with
advanced logic and memory devices, the dry etching process should be adopted to meet the needs of the
optical proximity effect correction (OPC) and reduced bias process [W. T. Chen and M. Kamma: Proc. SPIE 3412 (1998) 149.]. There are severe CD variations in
the dry etching process due to chrome (Cr) pattern density with various clear and dark fields. Through
experiments, on the CD variation was investigated in the wet etching process, as well as in the dry etching
process. This work focused on the tracing-determining the actual cause of the loading effect. It was
revealed that what accounts for a major portion of the loading effect is not the Cr dry etching process, but
the rescattering of electrons of the electron-beam exposure system. Rescattered electrons in this article
refers to electrons that are reflected between the specimen and the lower parts of the electron-beam
column and expose the unexposed area. In this paper, the existence of rescattered electrons was
experimentally confirmed with a 10 kV acceleration-voltage system and the CD variation by reflected
electrons was also investigated.