bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and treatment of cardiovascular disease and traditional risk factors in Australian adults with renal insufficiency
Authors: BRIGANTI ESTHER M , KERR PETER G , SHAW JONATHAN E , ZIMMET PAUL Z , ATKINS ROBERT C
Published: February 2005

Aim:  To evaluate the prevalence and treatment of cardiovascular disease and traditional cardiovascular disease risk factors in Australian adults with renal insufficiency.

Methods:  The Australian Diabetes, Obesity and Lifestyle Study was a cross‐sectional survey of Australian adults undertaken in 1999–2000. Participants were categorized based on the Cockcroft–Gault estimated glomerular filtration rate in terms of normal renal function (<60 mL/min per 1.73 m2) and renal insufficiency (<60 mL/min per 1.73 m2). Outcome measures were the prevalence of cardiovascular disease, estimated risk of cardiovascular disease (20% over 10 years) and traditional cardiovascular risk factors, and frequency of pharmacological treatment of traditional cardiovascular risk factors.

Results:  Among adults with renal insufficiency, cardiovascular disease was present in 29.4 (95% CI: 25.1–33.6) per 100, with an additional 47.9 (95% CI: 44.9–50.9) per 100 having an estimated risk of cardiovascular disease (20% over 10 years). At least one cardiovascular risk factor was present in 90.1%. Hypertension and type 2 diabetes mellitus were three times more frequent, while hyperlipidaemia was nearly twice as frequent in those participants with renal insufficiency. Of those with renal insufficiency, 58.2% with hypertension were treated, with only 14.5% of this group being treated to current recommended target levels of blood pressure, while only 32.5% with hyperlipidaemia were treated, with 7.4% of this group being treated to target lipid levels.

Conclusion:  The present study demonstrates significant scope to reduce the high burden of cardiovascular risk factors in Australian adults with renal insufficiency in the general community, through treatment of traditional risk factors for cardiovascular disease.
Economic evaluation of centre haemodialysis and continuous ambulatory peritoneal dialysis in Ministry of Health hospitals, Malaysia
Authors: HOOI LAI SEONG , LIM TECK ONN , GOH ADRIAN , WONG HIN SENG , TAN CHWEE CHOON , AHMAD GHAZALI , MORAD ZAKI
Published: February 2005

Background: This is a multi‐centre study to determine cost efficiency and cost effectiveness of the Ministry of Health centre haemodialysis and continuous ambulatory peritoneal dialysis (CAPD) programme.

Methods: Forty‐four haemodialysis and 11 CAPD centres were enrolled in this study in 2001. Sixty patients, 30 from each modality, were evaluated. Micro‐costing was used to determine costs.

Results: The number of haemodialyses conducted ranged from 402 to 23 000 procedures per year, while for CAPD, output ranged from 70 to 2300 patient months/year. Cost ranged from RM79.61 to RM475.79 per haemodialysis treatment, with a mean cost of RM169 per HD (USD 1 = RM 3.80). The cost of CAPD treatment ranged from RM1400 to RM3200 per patient month, with a mean of RM2186. Both modalities incurred similar outpatient costs. The cost of erythropoeitin per year is RM4500 and RM2500 for haemodialysis and CAPD, respectively. The number of life years saved is 10.96 years for haemodialysis and 5.21 years for CAPD. Cost per life year saved is RM33 642 for haemodialysis and RM31 635 for CAPD. The cost for land, building, equipment, overheads, and staff were higher for haemodialysis, while consumables and hospitalization cost more for CAPD. Sensitivity analysis was performed for two discount rates (3 and 5%), varying erythropoietin doses and maximum and minimum overheads. Relative cost effectiveness of haemodialysis and CAPD was unchanged in all sensitivity scenarios, except for overhead costs, which influenced the cost effectiveness of HD.

Conclusion: It is economically viable to promote the use of both CAPD and haemodialysis because the cost effectiveness of both are nearly equal.
Describing Use of Nursing Interventions for Three Groups of Patients
Authors: Dochterman Joanne , Titler Marita , Wang Jenny , Reed David , Pettit Debra , Mathew‐Wilson Mary , Budreau Ginette , Bulechek Gloria , Kraus Vicki , Kanak Mary
Published: February 2005

Purpose:

To describe the nursing interventions used most frequently during an acute hospital stay for three patient groups.

Methods:

Analysis of nursing interventions documented by use of the Nursing Interventions Classification (NIC) contained in an electronic clinical database obtained from 33 general inpatient units in one large health care facility from July 1, 1998, to June 30, 2002. The numbers of hospitalizations for each sample in the analyses were: 1,435 in the heart failure group, 567 in the hip fracture procedures group, and 11,756 in the fall prevention group.

Findings:

The mean number of interventions done at least once during a single hospitalization ranged from 18 to 22 for the three samples. For the total number of patient hospitalizations for each group, the number of interventions ranged from 94 for the hip fracture procedures sample to 182 for the fall prevention sample. Seven interventions were done twice or more a day in at least 20% of the sample in all three groups. Patterns of interventions during the first 6 days of care differed by intervention and sample, indicating that nursing care was individualized.

Conclusions:

The results indicate the types of information that can result from analysis of actual clinical nursing data documented with standardized language (Nursing Interventions Classification) in a nursing information system. The knowledge of nursing interventions used in clinical practice has major implications for staff development and nursing education. The information is also useful in making staffing decisions for different types of patient populations.
In situ laser power measurement at the focus of microscope objectives used in optical tweezers
Authors: Viana N. B. , Rocha M. S. , Mesquita O. N.
Published: February 2005

We discuss measurements of the laser power at the focus of high numerical aperture objectives used in optical microscopy and optical tweezers. For a given power, the focused incident laser beam heats a small mercury bead that jumps when it reaches the boiling temperature of water, the medium used in the experiments. From the size of the mercury beads, the heat conductivities of water and glass-slide, and the absorption coefficient of mercury for the laser wavelength used, the incident power can be obtained using the solution of the associated heat problem. This problem is mapped onto the problem of a charged conducting sphere embedded in a semi-infinite medium of dielectric constant ε1, separated from another semi-infinite medium of dielectric constant ε2.
The quantum mechanical picture of the world
Authors: Cassinello Andrés , Gallego Antonio
Published: February 2005

We present a picture of the world suggested by quantum mechanics in a manner accessible to nonspecialists. We construct a model of subatomic reality and use the model to present a geometrical proof of the Kochen–Specker–Bell no-go theorem, which demonstrates that the properties of a microscopic system are not completely defined before we look at it.
Growth of High-Quality CsLiB6O10 Crystals from Materials Mixed in Aqueous Solution
Authors: Nishioka Muneyuki , Kawamura Fumio , Yoshimura Masashi , Mori Yusuke , Sasaki Takatomo
Published: February 2005

CsLiB6O10 crystals were grown from high-quality sintered powder using the Top-Seeded Solution Growth (TSSG) method. The starting materials were prepared by calcination via a homogeneous precursor mixed in aqueous solution. The crystal grown possessed approximately a two-fold higher bulk ultraviolet laser-induced damage threshold than conventional crystals and fused quartz. The IR absorption intensity due to hydroxyl ions in the crystal was revealed to be almost the same as that in conventional crystals.
Modeling and Analytical Calculation of Strain Induced by Gradual Variation of Composition in Bulk InxGa1-xAs Mixed Crystal
Authors: Islam Md. Rafiqul , Hiroki Akira , Yamada Masayoshi
Published: February 2005

An axially symmetrical strain model has been proposed to evaluate the residual strain distribution induced by gradual variation of composition in a bulk mixed crystal system. The strain components in cylindrical coordinates are analytically derived by using a stress function technique. The results obtained from the model demonstrate that the quantitative amount of strains and their distributions are highly sensitive to the compositional profile and its range. The strain model is confirmed by comparing photoluminescence (PL) and energy dispersive X-ray (EDX) experiments performed in a bulk In
x
Ga1-x
As mixed crystal grown by the conventional freezing method. It is found from the PL and EDX results that there exists a large amount of strain induced by gradual variation of composition, which is well explained by the model proposed here.
Development of a Compact Divertor Simulator Excited by Helicon-Wave Discharge
Authors: Aramaki Mitsutoshi , Kato Koji , Goto Motoshi , Muto Sadatsugu , Morita Sigeru , Sasaki Koichi
Published: February 2005

We have developed a high-density H2 plasma source excited by helicon-wave discharge. By optimizing the antenna shape, the diameter of the discharge tube, and the magnetic field strength, a high electron density close to 1×1013 cm-3 was achieved at an rf power of 3 kW and a H2 gas pressure of 30 mTorr. The high-density H2 plasma source can be used as a compact divertor simulator in nuclear fusion research.
Extension of Measurable Region of Object Vibration Phasor in Phase-Modulated TV Holographic Interferometry: Experiment
Authors: Kojima Kentaro , Miyazaki Takeshi , Nojima Ken , Yamamoto Hirotaka , Sasaki Yasuhito
Published: February 2005

In this paper, we present an experiment based on the previously reported theory concerning the extension of the measurable region of object vibration phasor in phase-modulated TV holographic interferometry. This theory is based on the following facts: (1) the modulation of speckle interference image is proportional to the Bessel function, (2) its argument indicates the distance between the phasors of phase modulation and object vibration in the complex plane, and (3) the modulation increases as the Bessel function argument approaches zero. The phase modulation phasor is scanned, and at each pixel, one seeks the phase modulation phasor producing the maximum modulation. From the modulations produced by four phase modulation phasors adjacent to the sought phase modulation phasor, the object vibration phasor can be calculated. We analyzed the vibration of a phosphor-bronze rectangular plate with free sides, which were vibrated at the center by a piezoelectric transducer (PZT). Twenty-one phase modulation phasors were employed. The results of measurement were presented, and it was confirmed that the object vibration phasor can be measured in the wider region based on the theory concerning the extension of the measurable region.
High Performance Low Temperature Polycrystalline Silicon Thin Film Transistors on Non-alkaline Glass Produced Using Diode Pumped Solid State Continuous Wave Laser Lateral Crystallization
Authors: Hara Akito , Takei Michiko , Takeuchi Fumiyo , Suga Katsuyuki , Yoshino Kenichi , Chida Mitsuru , Kakehi Tatsuya , Ebiko Yoshiki , Sano Yasuyuki , Sasaki Nobuo
Published: February 2005

High performance low temperature polycrystalline silicon (poly-Si) thin film transistors (TFTs) with large grains were created using diode pumped solid state (DPSS) continuous wave (CW) laser lateral crystallization (CLC), employing fabrication processes at 450°C. Field-effect mobilities of 566 cm2/Vs for the n-channel and 200 cm2/Vs for the p-channel were obtained for a thick Si film (100–150 nm) on a 300×300 mm non-alkaline glass substrate. The high performance of the TFTs is attributed to the predominantly (100)-oriented very large grains. With a decreasing Si-film thickness, the grain size decreases, and the surface orientation of the grain changes from (100) to other orientations. These effects lead to reduced field-effect mobility with decreasing Si-film thickness, but it is easy to obtain a high field-effect mobility of over 300 cm2/Vs, even with a 50 nm thick Si film, without special processing techniques. A complementary metal oxide semiconductor (CMOS) ring oscillator was fabricated using a thin Si film 65 nm thick to demonstrate the high circuit performance of CLC poly-Si TFTs by applying the simplest CMOS process technology. A delay of 400 ps/stage at a gate length of 1.5 µm and a supply voltage of V
dd=5.0 (V) was produced on a large non-alkaline glass substrate utilizing a fabrication temperature of 450°C. This crystallization method will lead to the fabrication of high-performance and cheap Si-LSI circuits on large non-alkaline glass substrates.
Dual Elementary-Steps Growth Mechanism of CdHg(SCN)4(H6C2OS)2 Crystals
Authors: Wang Kunpeng , Zhang Jianxiu , Sun Daliang , Wang Shenglai , Yu Wentao , Guo Shiyi
Published: February 2005

A new dual elementary-steps growth mechanism was observed during our research on the CdHg(SCN)4(H6C2OS)2 (CMTD) crystals. Namely two types of elementary-step sources with different step height can be produced on the same crystal surface during the growth of some crystals. Furthermore the sum of these elementary-step heights is equal to the corresponding interplanar distance d

h
k
l
. The heights of these elementary steps were determined by crystal structure as well as growth motif and they have no relation to crystal defects. The elementary steps referred in this paper are completely different to sub-step mentioned by Min in 1988. Only one step height h was included in normal growth rate formulas for the dominant crystal growth theories at present such as BCF spiral growth mechanisms and the classic two-dimensional nuclear growth modes. Without considering the effects of the dual elementary-steps h
1 and h
2 to the growth procedure, the classic formulas containing the parameter h (step height) should be modified when they are applied to the research on crystals growing with dual elementary-steps growth mechanism.
Design of Sequential Lateral Solidification Crystallization Method for Low Temperature Poly-Si Thin Film Transistors
Authors: Park Ji-Yong , Park Hye-Hyang , Lee Ki-Yong , Chung Ho-Kyoon
Published: February 2005

Sequential lateral solidification (SLS) is known as a promising method for making low-temperature poly-Si thin film transistors (LTPS TFT) with superior performance for the fabrication of highly circuit-integrated flat panel displays such as TFT liquid crystal display (LCD) and TFT organic light Emitting diode (OLED). In this work we studied the dependence of TFT characteristics on SLS poly-Si grain width and suggested the methods of designing SLS mask pattern to achieve uniform TFT performance. We varied the width of the poly-Si grain by employing the 2-shot SLS mask pattern with different overlaps between the 1st and 2nd laser pulses. The width of the poly-Si grain decreased with decreasing the overlap. However, the measured TFT characteristics revealed that the width of the poly-Si grain negligibly influences the device properties. We could achieve the TFT mobility of approximately 350 cm2/V·s for the overlap of not less than 1 µm. We suggested that the SLS mask pattern (x, y) should be designed such that 2+y≤x<2 (C-SLG distance) and y > (optical resolution), where x is the spacing of the laser-absorbed region and y is the spacing of the laser-nonabsorbed region on the substrate.
Microroughness Reduction of Tungsten Films by Laser Polishing Technology with a Line Beam
Authors: Kim Yong-Gi , Ryu Je-Kil , Kim Dae-Jin , Kim Hyun-Jung , Lee Sungman , Cha Byung Heon , Cha Hyungki , Kim Cheol-Jung
Published: February 2005

An optical polishing technology utilizing a line shaped excimer laser beam was introduced to reduce the microroughness of the tungsten films deposited onto the Si wafer surface. The results of the microroughness reduction and the comparisons were made before and after the line beam irradiations for as-grown and post-chemical mechanical planarization (CMP) tungsten films as a function of irradiated laser wavelength, in 248 nm and 308 nm, laser fluence, and the irradiated number of pulses. Characterizations of the microroughness were performed by atomic forced microscopy. The root-mean-square (RMS) roughness and peak-to-valley, R
p-v, roughness of the as-grown tungsten films were decreased by about 30%–40% compared with the initial values. The RMS roughnesses of the post-CMP tungsten films were 25–30 Å for a 5 µm×5 µm measurement. Fluctuations of the reduced microroughness were mainly caused by the beam inhomogeneity and local distributions of the hot (peak energy) spots along or across the line beam. The lowest RMS roughness of 8.0–8.4 Å was obtained for the post-CMP tungsten films by the irradiation of 30 pulses of 308 nm with a fluence of 100 mJ/cm2. Irradiation of the 248 nm and 308 nm homogenized flat-top line beam reduced the peak-to-valley roughness, R
p-v, of the post-CMP tungsten films down to 1/3 of its initial value. It was found that the optimum number of pulses for microroughness diminution of the post-CMP tungsten film is 50 pulses with a fluence of 150 mJ/cm2. The wavelength dependency of the microroughness diminution was not surprising, but 308 nm irradiation showed a slightly better performance with consistent results than the 248 nm irradiation did.
Nondestructive Characterization of a Series of Periodic Porous Silica Films by in situ Spectroscopic Ellipsometry in a Vapor Cell
Authors: Negoro Chie , Hata Nobuhiro , Yamada Kazuhiro , Kikkawa Takamaro
Published: February 2005

Pore size distributions in a series of periodic porous silica low-dielectric-constant (low-k) films were determined by the analysis of adsorption/desorption isotherms of heptane. The isotherms were obtained from in situ spectroscopic ellipsometric measurements at room temperature in a vapor cell. The porous silica low-k films were prepared by the spin coating of a mixture of silica precursor and alkyltrimethylammoniumchloride surfactant template solutions. A systematic increase in pore diameter with an increase in the alkyl chain length of the template molecules was observed. It is concluded that the in situ spectroscopic ellipsometry in a vapor cell as a nondestructive technique of characterizing pore structures in porous low-k films has the potential to clearly distinguish such a slight difference in pore diameter as is caused by only –(CH2)2– in a template molecular structure.
A Novel Extremely Broadband Superluminescent Diode Based on Symmetric Graded Tensile-strained Bulk InGaAs
Authors: Wang Shu-Rong , Wang Wei , Liu Zhi-Hong , Zhu Hong-Liang , Zhang Rui-Ying , Zhao Ling-Juan , Zhou Fan , Ding Ying , Wang Lu-Feng
Published: February 2005

A novel broadband superluminescent diode (SLD), which has a symmetric graded tensile-strained bulk InGaAs active region, is developed. The symmetric-graded tensile-strained bulk InGaAs is achieved by changing the group III TMGa source flow only during its growth process by low-pressure metalorganic vapor-phase epitaxy (LP-MOVPE), in which the much different tensile strain is introduced simultaneously. At 200 mA injection current, the full width at half maximum (FWHM) of the emission spectrum of the SLD can be up to 122 nm, covering the range of 1508–1630 nm, and the output power is 11.5 mW.
Effective Demagnetizing Factors of Second-Order Magnetocrystalline Anisotropies in Ferromagnetic Resonance Kittel Formula
Authors: Kohmoto Osamu
Published: February 2005

The effective demagnetizing factors (N

x

e and N

y

e) of the second-order magnetocrystalline anisotropies of cubic and hexagonal single crystals (K
2 and K

u2) for use in Kittel's ferromagnetic resonance formula are derived using previously proposed equations. The saturation magnetization is assumed to align with a static field. Six arrangements for films with the static field applied in the film plane are calculated: (1) perpendicular uniaxial anisotropy, (2) in-plane uniaxial anisotropy, (3) cubic-crystal (001) face, (4) cubic-crystal (011) face, (5) cubic-crystal (111) face, and (6) oblique anisotropy films.
An Optical Configuration Based on Flying Head Structure for Near-Field Recording
Authors: Mizuno Takeshi , Kojima Naoto , Hitosugi Taro , Sako Kageyasu , Watanabe Kenjiro
Published: February 2005

We report an optical configuration with a flying head for a near-field recording system. The configuration consists of a fixed optical unit and condensing optics based on the flying head structure. While the fixed optical unit includes a light source and a signal-detection unit, the condensing optics include a solid immersion lens (SIL) embedded in the flying slider and infinite objective lens arranged on the flying slider. Free-space propagation using a collimated beam is employed to optically connect these two units. After we investigated the head structure and its fabrication process, we evaluated the fabricated optical flying head, both as an optical head and a flying head. The jitter was 8.87% when the shortest mark length was 0.364 µm. The C/N ratio was 49.53 dB for 0.2 µm of the mark length. The tolerances of relative tilt and decenter between the two optical axes of the fixed optical unit and the condensing optics which were derived experimentally were ±0.3 deg and ±150 µm. These results suggest that the optical configuration is adequately practical even for use in mass production.
Fluorine-Doped SiO2 Films Made from Silicone and Polytetrafluoroethylene Using an F2 Laser
Authors: Takao Hiromitsu , Okoshi Masayuki , Inoue Narumi
Published: February 2005

In the present paper, we propose a novel method which permits us to fabricate fluorine-doped silicon dioxide (F-doped SiO2) films on various substrates at room temperature. The films were selectively grown on a substrate by simultaneous 157-nm F2 laser illumination of a silicone rubber target, a polytetrafluoroethylene (PTFE) target, and the substrate. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra showed that the films had a uniform fluorine concentration in the depth direction and no contaminants, such as carbon and hydrocarbon. The films were photochemically grown on the substrate in an atmosphere of gases evolved from silicone and PTFE by F2 laser illumination. The relative dielectric constant of the films was lower than that of the SiO2 films grown by F2 laser illumination without a PTFE target, namely, 3.6 at a laser fluence of 22 mJ/cm2. The F-doped SiO2 film formed at a higher a laser fluence had a lower refractive index and lower relative dielectric constant.
Organic Dye-Doped Thin Films for Wavelength Conversion and Their Effects on the Photovoltaic Characteristics of CdS/CdTe Solar Cell
Authors: Hong Byung-Chul , Kawano Katsuyasu
Published: February 2005

For the improvement of the conversion efficiency of CdS/CdTe solar cells by applying the wavelength conversion properties, the spectroscopic studies of the fluorescent laser dye Rhodamine 6G (Rh6G)-doped into polyvinylbutyral (PVB) and polymethylmethacrylate (PMMA) were carried out. It was found that all the photoluminescence excitation (PLE) spectra below 540 nm were effectively converted to photoluminescence (PL) spectra in the wavelength region above 550 nm where the solar cell possessed a high spectral quantum efficiency. The external quantum efficiencies of PVB:Rh6G and PMMA:Rh6G films were estimated to be 0.9±0.05 and 0.4±0.1, respectively. When the PVB:Rh6G film was placed on the top of the CdS/CdTe solar cell, both short-circuit current and conversion efficiency increased by 11% compared with the cell with no film.
Effect of Microstructure on Microwave Dielectric Properties of Al2O3-Added Ba(Zn1/3Ta2/3)O3 Ceramics
Authors: Kim Min-Han , Nahm Sahn , Lee Woo-Sung , Yoo Myong-Jae , Park Jong-Cheol , Lee Hwack-Joo
Published: February 2005

The effects of Al2O3 additive on the microstructure and microwave dielectric properties of Ba(Zn1/3Ta2/3)O3 (BZT) ceramics were investigated. The BZT ceramics has a 1:2 ordered hexagonal structure. The degree of the 1:2 ordering did not decrease with the addition of Al2O3. Grain growth occurred and the liquid phase formed for the Al2O3-added BZT ceramics sintered above 1580°C. The liquid phase contains high concentrations of Ba and Al ions, which could be responsible for the grain growth. When a small amount of Al2O3 was added, the relative density slightly decreased but the Q value was markedly enhanced. The increase in the Q value was not related to the relative density or the 1:2 ordering. In contrast, the improvement in the Q value occurred in specimens in which grain growth occurred. Therefore, the increase in the grain size is considered to be responsible for the improvement in the Q value of Al2O3-added BZT.
Compound Linear Ultrasonic Motor Based on Shaking Beam
Authors: Lee Dong-Kyun , Han Deuk-Young , Borodinas Sergejus , Vasiljev Piotr , Yoon Seok-Jin
Published: February 2005

The transformation of high-frequency vibrations of piezoelectric elements into continuous linear motion of a slider is one of the main tasks of a linear piezoelectric motor. To produce a high thrust force in the piezoelectric linear actuator, we proposed the compound piezoelectric linear actuator based on a “shaking beam” excited by two sources of longitudinal mechanical vibrations shifted by π/2. The compound actuator consists of two shaking beams and is rigidly fastened. The finite element method (FEM) was used to define structural and electrical boundary conditions for the compound piezoelectric actuator. FEM analysis showed that the compound actuator's trajectory was elliptical. Experimental research has shown that the compound piezoelectric actuator has high thrust force.
Amorphous In-Plane Switching Twisted Nematic Liquid Crystal Displays Fabricated without Rubbing Process Show a Wide Viewing Angle and Fast Response Characteristics
Authors: Kobayashi Kazuya , Fujiwara Taku , Oka Shinichirou , Iwamoto Yoshihisa , Toko Yasuo , Takahashi Taiju , Kimura Munehiro , Akahane Tadashi
Published: February 2005

Excellent electrooptical (EO) characteristics of an amorphous in-plane switching twisted nematic liquid crystal display, which is fabricated without the conventional rubbing treatment, are demonstrated. A wide and uniform viewing angle characteristic without showing gray scale inversion or color shift can be realized by the multidomain alignment, which is called `amorphous alignment'. The response time was much less than 17 ms and relaxation time was as fast as 10 ms. The device may contribute not only to the simplification of the production process but also to significant improvement of the response time, compared with the conventional rubbed liquid crystal display.
Computer Simulation of Transition Processes between Bistable States in Bistable Nematic Liquid Crystal Cell Using Breaking Phenomenon of Surface Anchoring
Authors: Takahashi Taiju , Tsuchida Shinya , Udagawa Masaru , Saito Susumu
Published: February 2005

The transition process between bistable states in the bistable nematic (Bi-Nem) cell based on the anchoring breaking phenomenon has been strictly simulated by computer. In our simulation, the surface tilt angle dependence of the contribution of azimuthal anchoring to the surface free energy density has been taken into account. This leads to successful reproduction of the bistable operation of the Bi-Nem cells by the computer simulation. As a result, it has been clarified that in the transition process from the uniform state to the twisted state, the molecular orientation takes the 270 deg. twisted state at first and then changes toward to the 180 deg. twisted state. From our simulations, it is confirmed that the bistable transition occurs in limited regions of polar and azimuthal anchoring energy on the slave plate.
Mechanical Rotor Model for Fluorinated Terphenyl Liquid Crystals
Authors: Ma Heng , Xu Jun , Okada Hiroyuki , Sugimori Shigeru , Onnagawa Hiroyoshi , Toriyama Kazuhisa
Published: February 2005

A mechanical model is established to explain phase behaviors and thermal properties of liquid crystals (LCs). We postulate that LC phases are micro-machine systems consisting of an ensemble of molecular rotors. The phenomena of the thermal stability of phase and polymorphism are interpreted in terms of mechanics that involve basic parameters such as center of gravity (G), moment of inertia (I
A), eccentricity (ε) and mass deviation along the molecular axis (δ). A novel concept of “slim isomer” and “fat isomer” for the fluorinated LC system is proposed. Furthermore, the parameter ωc, critical rotational velocity around the long molecular axis is adopted to analyze the thermal stability at the critical point. It is determined that the value of ωc is a key parameter for the characterization of each homologous series.
Thermo-optically Tunable Wavelength Filter with Permanent Refractive Index Grating into Azo-Polymer Waveguide
Authors: Hattori Toshiaki , Shibata Tomoaki , Onodera Shinji , Kaino Toshikuni
Published: February 2005

Refractive index gratings into an azo-polymer waveguide were fabricated by irreversible photo-induced bleaching (photodecomposition) of the polymer. The waveguide grating was formed by exposure of an interference pattern from two laser beams. Coupling characteristics of the waveguide grating were investigated around the infrared wavelength region. The coupling efficiency of the grating was dependent on the polarization direction of the guiding beam. This phenomenon seems to result from the anisotropic refractive index change due to the photobleaching at the vertical plane of the film. Furthermore, we demonstrated a tunable wavelength filter with the refractive index gratings into the azo-polymer waveguide. This filter has a spatial tunability, i.e., wavelength tuning can be attained due to thermooptic refractive index change of the polymer. In the fabricated wavelength filter, the diffraction pass wavelength is tuned over 19 nm at around the 1.3 µm from 5°C to 65°C.
Bottom Electrode Crystallization of PZT Thin Films Deposited by Laser Ablation
Authors: Mardare Andrei I. , Mardare Cezarina C. , Pinheiro Ernesto , Joanni Ednan
Published: February 2005

The bottom electrode crystallization (BEC) method was applied to the crystallization of lead zirconate titanate (PZT) thin films deposited by laser ablation over Si/SiO2/Ti/Pt structures, with the platinum films being deposited at two different temperatures. The results were compared with those obtained by rapid annealing with halogen lamps and furnace annealing. PZT films crystallized over platinum deposited at lower temperature have larger grains and tend to have a (111) preferential orientation, while those crystallized on platinum deposited at higher temperature have smaller grain sizes and tend to have a (101) preferred orientation. The results are consistent with the increase of titanium diffusion as the temperature for platinum deposition increases, having as a consequence a greater number of nucleation centers on the platinum surface. The ferroelectric properties of the films crystallized with the BEC method are good, being similar to those obtained with the other crystallization methods using the same parameters.
Er3+ Photoluminescence from Er-doped Silicon-Rich Silicon Oxide Films Deposited by Laser Ablation of a Si:Er Target in an Oxygen Atmosphere
Authors: Ha Jeong Sook , Jang Young Rae , Yoo Keon Ho , Bae Chang Hyun , Nam Sang Hwan , Jeon Ji Seon , Park Seung Min
Published: February 2005

We have developed a new pulsed laser deposition method for fabricating Er-doped silicon-rich silicon oxide (SRSO:Er) films. A target composed of a pure Si disk and an Er metal strip was ablated by a line-focused laser beam in oxygen atmosphere. The oxygen concentration that determines the relative concentrations of the three phases (Si–Si, SiO
x
, and SiO2) in the film was easily controlled by varying the ambient oxygen pressure. The photoluminescence intensity at 1.54 µm from Er3+ ions was strongly dependent on the amount of the Si–Si phase in the SRSO:Er films.
Adsorption and Absorption of Nitrogen on a W(001) Surface Studied by Thermal Desorption Spectroscopy
Authors: Kanama Daisuke , Tanaka Masatoshi , Matsuoka Hironori , Shudo Ken-ichi , Fukutani Katsuyuki , Koide Tsuneharu
Published: February 2005

The adsorption states of nitrogen on a W(001) surface, particularly the β1 state appearing at high coverage, have been studied by two new approaches based on thermal desorption spectroscopy (TDS). First, the isotope 15N was used to discriminate the β1 state from the β2 state saturated with 14N at low coverage. It is proposed for the β1 state formation that 15N exposed later stamps 14N into the octahedral site of the subsurface mainly through single steps around which the atomic distance is extended by nitrogen-induced contracted islands. Secondly, a vicinal surface was investigated to elucidate the role of the steps. Only a small β1 peak was found, which is interpreted to be a result of suppressed formation of contracted islands due to a large number of surface defects. Other features observed on the vicinal surface are well explained with the proposed model.
Investigation of Self-Organized Steps and Terraces in SrTiO3 (001) Substrate Inclined in [110] Direction by Scanning Tunneling Microscopy
Authors: Cho Gyu Bong , Yamamoto Masahiko , Endo Yasushi
Published: February 2005

The features of self-organized steps and terraces on SrTiO3 (001) substrates inclined in a [110] direction with various inclined angles (α) have been investigated by scanning tunneling microscopy (STM). The well-defined triangular step edges forming nanodot structures are observed on the surface. The surface features of SrTiO3 substrates inclined in the [110] direction consist of the combinational features of substrates in the [100] and [010] inclined directions. Details of the distributions of step heights, terrace widths and lengths of step edge dependent on inclined angles are described. The formation of double, triple and triple half steps is observed in self-organized substrates. The surface after self-organization maintains the same ratio of step height to terrace width. The terminations of TiO2 and SrO planes on the surface are observed visually by an analysis of surface structures. The inclined angle of the substrate inclined in the [110] direction is expected to be an important factor for controlling the density of nanodot structures.
Efficiency of Laser Plasma Kα Emission for Time-Resolved X-ray Imaging
Authors: Ohkubo Takeru , Kinoshita Kenichi , Zhidkov Alexei , Hosokai Tomonao , Kanegae Yukio , Uesaka Mitsuru
Published: February 2005

Laser Plasma X-rays (LPX) with a duration of 10 ps or less, emitted from a solid target irradiated by a femtosecond laser pulse, is useful for time-resolved measurements. The intensity of this radiation is 4×109 photons/shot/4πsr at maximum, which corresponds to the conversion efficiency of laser energy into Kα X-rays of 3.4×10-5. By simulations of the interaction of a laser pulse with a solid target, the efficiency is shown to increase more than ten times by suppressing the energy of a laser prepulse.
A New Multifunctional Three-Dimensional Tactile Sensor Using Three Coils
Authors: Chi Zhiyu , Shida Katsunori
Published: February 2005

A new three-dimensional tactile sensor has been developed imitating the human finger based on multifunctional sensing technology. This sensor consists of three coils and two mediums. A step-by-step method is used to realize the multifunctional sensing and in each step, a different quantity is sensed. The processing method in spherical coordinates is introduced to resolve the force vector. On the basis of the unique structure of the sensor and ingenious measurement methods, the authors realized the aim of testing more than one quantity, that is, the magnitude and two direction angles of the force vector, with a single sensor. Here, we discuss the design guideline for and the structure of the sensor, with in-depth studies of the step-by-step measurement method and the experimental results.
Detection Limits of Trace Elements for Wavelength Dispersive Total X-Ray Fluorescence under High Flux Synchrotron Radiation
Authors: Awaji Naoki , Nomura Kenji , Doi Shuichi , Takemura Momoko , Kamimuta Yuichi , Takahashi Mamoru , Ozaki Shinji , Takahashi Masao , Iihara Junji , Miyatake Kenichiro , Yamazaki Noboru , Inoue Katsuaki , Yagi Naoto , Komiya Satoshi
Published: February 2005

The performance of wavelength dispersive (WD) total reflection X-ray fluorescence (TXRF) equipment in conjunction with the high flux quasi monochromatic X-ray of beamline 40XU at the synchrotron radiation (SR) facility SPring-8 has been explored. To obtain a good detection limit for the trace elements, the origin of background events has been studied and we found that the main part of the background is generated in the substrate, presumably by the photoelectron bremsstrahlung. The optimization of the grazing angle of the incident X-ray has been carried out to minimize the background signals in addition to maximizing the fluorescence signals to obtain a good lower limit of detectability (LLD). We evaluated the LLD for light through heavy elements. We obtained the LLD of 5.0×108 atoms/cm2 for Ni with the energy resolution of 50 eV. Furthermore, by applying the surface concentration technique for an 8 inch Si wafer, we achieved the Ni LLD of 3.7×106 atoms/cm2 for the first time, which is lower than the LLD obtained from chemical analysis such as inductively coupled plasma-mass spectrometry (ICP-MS).
Defect Modes in Two-Dimensional Quasiperiodic Photonic Crystal
Authors: Wang Yiquan , Jin Chongjun , Han Shouzhen , Cheng Bingying , Zhang Daozhong
Published: February 2005

The defect modes and transmission property of a two-dimensional quasiperiodic photonic crystal (QPC) with defects are studied experimentally and theoretically. It is found that the defects, introduced by removing the dielectric cylinders in the central octagon, may result in various defect modes and resonant frequencies. If the defects possess the same rotational symmetry, the resonant frequencies of the defects are identical. However, the corresponding transmittances can be quite different. This is attributed to the different field distribution leading to various coupling strength between the incident and transmitted waves. When it is symmetrically distributed against the central line which is perpendicular to the incident direction, the transmittance enhances drastically. Based on the wave coupling theory, a simple model is given to explain this phenomenon.
Vision Chip with Electrical Fovea Motion
Authors: Nakagawa Yoshihiro , Deguchi Jun , Kurino Shim , Koyanagi Mitsumasa
Published: February 2005

A foveated vision of a human visual processing system is known to reduce the amount of information passed to subsequent processing layers significantly and lends itself to fast image processing and pattern recognition tasks. In order to realize such a vision chip based on the foveated vision processing system, we propose two concepts: the receptive field and the refractory period. Our vision chip can focus the fovea on a target electrically using these concepts.
Three-Dimensionally Stacked Analog Retinal Prosthesis Chip
Authors: Deguchi Jun , Watanabe Taiichiro , Nakamura Tomonori , Nakagawa Yoshihiro , Fukushima Takafumi , Kurino Shim , Abe Toshiaki , Tamai Makoto , Koyanagi Mitsumasa
Published: February 2005

As blind patients with an intact optic nerve and damaged photoreceptor cells increase in number in recent years, there has been a growing interest in visual prostheses by electrically stimulating their retinas. Previous clinical studies indicated that blind patients perceive a controlled electrical current applied to a small area of the retina via electrodes as a spot of light. We propose a novel implantable device, so-called three-dimensionally (3D) stacked retinal prosthesis, which is composed of a photodetector, an image processor, electrical current generator circuits, and an electrode array on one chip. The spice simulation showed that our designed analog circuits for 3D stacked retinal prosthesis chip could output desirable electrical current with variable pulse width by controlling bias voltages.
Efficient Suppression of Substrate Noise Coupling in Complementary Metal-Oxide-Semiconductor Field-Effect-Transistor Technology
Authors: Yeh Wen-Kuan , Chen Shuo-Mao
Published: February 2005

In this work, we investigate the substrate noise coupling using S-parameter measurement. Radio frequency domain analysis shows that the noise isolation is strongly dependent on layout geometry, including the parameters such as P/N junction, physical separation distance, guard ring (GR), and deep N-well (DNW). We found that the noise coupling can be efficiently diminished by incorporating a GR and DNW structures.
Gate Engineering to Prevent NMOS Dopant Channeling for Nanoscale CMOSFET Technology
Authors: Park Sung Hyung , Kim Yong Goo , Ji Hee Hwan , Lee Hi Deok , Kim Jae Sung , Baek Seong Hak , Chang Hoon , Lee Jin Hyuk , Kim Kyoung Cheol , Song Byeung Soo , Bae Hui Koung , Kim Myung Ok , Lee Heui Seung , Kang Young Seok , Kim Dae Byung
Published: February 2005

It is shown that anomalous off-current fluctuation may happen due to phosphorous channeling through gate polysilicon during source/drain implantation particularly for the first phosphorus double-implantation scheme. It is proven that increased grain size by phosphorus predoping is the main cause of channeling. A stacked polystructure with an amorphous top layer and a columnar bottom layer is proposed to suppress the phosphorus channeling and hence to prevent the off-current fluctuation. It is shown that the proposed stacked polystructure is highly efficient in suppressing the phosphorus channeling without degradation of device performance.
Schottky Barrier Height Reduction and Drive Current Improvement in Metal Source/Drain MOSFET with Strained-Si Channel
Authors: Yagishita Atsushi , King Tsu-Jae , Bokor Jeffrey
Published: February 2005

The use of strain to reduce contact resistance and improve the drive current of the Schottky barrier source/drain metal-oxide-semiconductor (MOS) transistor is proposed. The advantages of this approach were shown by theoretical calculation based on the non-equilibrium Green's function formalism. Furthermore, the interface dipole theory was firstly applied to the calculation in order to clarify the effects of strain and Fermi-level pinning on the Schottky barrier height. The calculated results indicate that bi-axial strain can reduce the Schottky-barrier height and increase complementary metal-oxide-semiconductor (CMOS) transistor drive current without disturbance of Fermi-level pinning, whereas hydrostatic strain has no effect on the barrier height because of the pinning. These results indicate the combination of the metal source/drain structure with a bi-axially strained Si channel can be beneficial for improving the drive current of nanoscale metal-oxide-semiconductor field-effect transistor (MOSFET).
Effects of Selecting Channel Direction in Improving Performance of Sub-100 nm MOSFETs Fabricated on (110) Surface Si Substrate
Authors: Nakamura Hidetatsu , Ezaki Tatsuya , Iwamoto Toshiyuki , Togo Mitsuhiro , Ikezawa Takeo , Ikarashi Nobuyuki , Hane Masami , Yamamoto Toyoji
Published: February 2005

We investigated the low field mobility and short channel characteristics of metal-oxide-semiconductor field-effect transistors (MOSFETs) on (110) surface Si substrates with various channel directions from the viewpoints of experiment and numerical simulation. We found that the mobility (µ) ratio of (110) substrates to (001) substrates (µ(110)/µ(001)) does not depend on the vertical electric field due to the identical surface roughness for (110) and (001) substrates. We verified mobility enhancement and its channel direction dependence by conducting a detailed carrier transport simulation using a full band model and relaxation time approximation. We obtained good threshold voltage (V
th) lowering characteristics due to the suppression of channeling at the source and drain (SD) extension by implant sequence control. Our results showed that the improvement in propagation delay time (C
V/I) and on-current ratio of nMOS to pMOS (I
on
n/I
on
p) obtained by using an optimized combination of channel directions and a (110) surface Si substrate is attractive for future LSIs down to the sub-100 nm region.
Characterization of Plasma Nitridation Impact on Lateral Extension Profile in 50 nm N-MOSFET by Scanning Tunneling Microscopy
Authors: Fukutome Hidenobu , Saiki Takashi , Hori Mitsuaki , Tanaka Takuji , Nakamura Ryou , Arimoto Hiroshi
Published: February 2005

The electrical performances of sub-50-nm n-metal-oxide-semiconductor field effect transistors (n-MOSFETs) are improved when a plasma nitridation process is used after the gate electrodes are formed. The maximum drive current is increased by 2% and the minimum gate length is shrunk by 5% while the off-leakage current is maintained. Inverse modeling suggested that these improvements were due to nitridation-induced changes in the two-dimensional carrier profile, and scanning tunneling microscopy confirmed that they were. The plasma nitridation decreased the overlapping length from 12 nm to 10 nm and increased the steepness of the lateral abruptness of the extension region from 3.6 nm/decade to 1.8 nm/decade. Such an optimized profile is thought to be mainly due to nitrogen suppressing the lateral anomalous diffusion of the arsenic piled-up along the interface between the silicon substrate and the insulating layer.
Nanoscale MOSFET with Split-Gate Design for RF/Analog Application
Authors: Yuan Jun , Woo Jason C. S.
Published: February 2005

Split-gate engineering has been studied to improve metal-oxide-semiconductor-field-effect-transistors (MOSFETs) down to the 45 nm regime, and it is shown that a properly designed split-gate device can improve both frequency performance and intrinsic gain for a wide range of channel lengths due to enhanced carrier transport and reduced short-channel effects. The relative gate length percentage in the split-gate device can optimize device performance based on cut-off frequency, intrinsic gain and threshold voltage considerations. Its output resistance behavior following drain-induced barrier lowering (DIBL) is studied; sidewall spacer width and substrate doping effect on device RF/analog performance are also discussed in this context.
Simple Wide-Band Metal-Insulator-Metal (MIM) Capacitor Model for RF Applications and Effect of Substrate Grounded Shields
Authors: Song Seong-Sik , Lee Seung-Wook , Gil Joonho , Shin Hyungcheol
Published: February 2005

In this paper, we propose a simple wide-band metal-insulator-metal (MIM) capacitor model incorporating the skin effect in the gigahertz regions. The proposed model accurately describes the frequency-dependent series resistance over a wide range of frequencies and hence enables the quality factor of the MIM capacitor to be predicted with high accuracy in the multi-GHz frequency regime. Since the proposed model consists of frequency-independent lumped elements, it can be easily implemented in simulation program with integrated circuit emphasis (SPICE)-compatible simulators. We also demonstrate the scalability of the proposed model for different device geometries. In addition, we present the characterized results for MIM capacitors under various substrate conditions including different shield materials.
Effect of Selective Oxidation Conditions on Defect Generation in Gate Oxide
Authors: Cho Heung-Jae , Lim Kwan-Yong , Jang Se-Aug , Lee Jung-Ho , Oh Jae-Geun , Kim Yong Soo , Yang Hong-Seon , Sohn Hyun-Chul
Published: February 2005

We studied the effect of selective oxidation conditions on gate oxide characteristics. Selective oxidation in hydrogen-rich wet ambient at 850°C–950°C was found to generate defects both at the SiO2/Si interface and in oxide bulk, resulting in a higher stress-induced leakage current. The degradation of the device can be explained by the incorporation of hydrogen into the gate oxide during a high-temperature selective oxidation process. The plasma reoxidation process induced fewer defects due to radical oxidation at low temperature.