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排序方式: 共有516条查询结果,搜索用时 15 毫秒
91.
Michio Tajima Masatoshi Ikebe Yoshio Ohshita Atsushi Ogura 《Journal of Electronic Materials》2010,39(6):747-750
We investigated the effect of Fe contamination on the electronic properties of dislocation clusters in relation to oxygen
precipitation in multicrystalline silicon (mc-Si). Photoluminescence (PL) spectroscopy and mapping were performed at room
and liquid-He temperatures on mc-Si wafers before and after Fe contamination. PL spectra consisted of the band-edge emission,
the 0.78-eV emission associated with oxygen precipitates, and the dislocation-related D-lines. The Fe contamination increased
the electrically active dislocation clusters. Part of these clusters acted as preferential oxygen precipitation sites, and
their electronic properties were not further influenced by the Fe contamination. 相似文献
92.
Daisuke Kosemura Maki Hattori Tetsuya Yoshida Toshikazu Mizukoshi Atsushi Ogura 《Journal of Electronic Materials》2010,39(6):694-699
Defects and stress gradually accumulate throughout various Si large-scale integration fabrication processes. It is essential
to monitor defects and stress carefully to suppress their unintentional introduction. In this study, we measured the stress
and crystal quality in shallow trench isolation (STI) samples by ultraviolet (UV)-Raman spectroscopy with an extremely high-resolution
wavenumber to evaluate the effect of post-annealing on the recovery of Si crystals. The variations of crystal quality in 200-mm
wafers with STI structures gradually decreased after post-annealing for 4 h, 6 h, and 8 h; however, there was no substantial
difference in the values of full-width at half-maximum of the Raman spectra. Precise measurements of variations of stress
and crystal quality were successfully performed by UV-Raman spectroscopy with a high-resolution wavenumber, which enabled
us to evaluate the STI process accurately. 相似文献
93.
In this study, a model in a computer simulation uses a single current dipole in a spherical homogeneous medium. Dipole parameters are estimated using a moving dipole procedure. Signal-to-noise ratio (SNR) is defined as the square-root of the ratio of the average signal power to the average noise power over all measurement points. At SNR>20, accurate estimation can be carried out independently of dipole depth and coil size. At SNR<20, dipole depth influences estimation error. When the dipole is located near the center of the sphere, the measurement region should include both extrema of the magnetic field to minimize estimation error. However, when the dipole is not so deep, the position of the measurement region does not influence estimation error. When SNR<4, estimation error increases as coil size increases. Coil size minimizing estimation error is determined by the ratio of environmental magnetic field noise to electrical noise. For a constant size of measurement region, increasing the number of measurement points decreases estimation error to a certain level. This error level depends on SNR 相似文献
94.
A small-signal analysis of direct modulation of laser diodes is presented. The analysis is valid over a wide frequency range, up to the frequency corresponding to the round trip time of the active region. This theory is best for laser diodes with small active regions but with large and complicated optical cavities. Optical resonances may occur in this range, resulting in a large response to direct modulation as a result of interaction of the lasing mode with the optical resonance. This theory can predict the linear response of the laser to direct modulation throughout this frequency range. It also predicts the lower frequency relaxation oscillation effect, thus unifying these different effects with a single treatment. The form of the modulation response is found to be the same as the standard relaxation oscillation formula, modified by a factor the form of which depends on the optics of the laser cavity alone 相似文献
95.
Determination of power reflectivity of quasi-graded distributedBragg reflectors using stopband width
Kurihara K. Numai T. Kosaka H. Ogura I. Sugimoto M. Kasahara K. 《Photonics Technology Letters, IEEE》1993,5(3):333-336
The authors examine the reflectivity of the quasi-graded distributed Bragg reflector using the stopband width. The stopband width of about 1000 Å for a reflectivity of about 99% is able to be measured with an accuracy of ± 1 Å. Thus, the reflectivity is determined with high accuracy from the stopband width. It is found that the quasi-graded distributed Bragg reflector is a high-quality reflector with high reflectivity and low resistance 相似文献
96.
Tomah Sogabe Akio Ogura Mitsuyoshi Ohba Yoshitaka Okada 《Progress in Photovoltaics: Research and Applications》2015,23(1):37-48
Spectral response of multi‐junction solar cell is complicated because of the interplay between external measurement conditions such as bias light intensity, monochromatic light intensity, bias voltage, and intrinsic electrical properties of series interconnected subcells. In this paper, we report an experimental study on the bias voltage‐dependent spectral response (SR) for multi‐junction solar cell. A self‐consistent iteration loop was developed from a nonlinear least square Powell hybrid algorithm that was used for curve fitting the experimental SR versus bias voltage data of each subcell. We demonstrated for the first time that this approach enabled us to derive the electrical parameters such as dark saturation currents (J0), shunt resistance (Rsh), series resistance (Rs), and spectra response (Jphoto) for each subcell of a Ga0.99In0.01As/Ge dual junction solar cell with stable convergence. The accuracies of the fitting results were confirmed by the agreement between the J–V curves calculated on the basis of these parameters and the experimental J–V curve of multi‐junction solar cell measured under AM1.5 and 1 sun condition. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
97.
InxGa1−xAs-based ohmic contacts which showed excellent contact properties for n-GaAs were demonstrated to be applicable to p-GaAs
ohmic contacts. These contacts, prepared by radio-frequency sputtering, provided low contact resistance (0.2 Ω-mm), excellent
thermal stability, smooth surface, and good reproducibility. The contact resistances had a weak dependence on the annealing
temperatures, which was desirable in a manufacturing view point. This weak temperature dependence was explained to be due
to a unique Schottky barrier height at the metal/p-InxGa1−xAs interface which does not depend on the In concentration in the InxGa1−xAs layer. The present experiment showed the possibility of simultaneous preparation of ohmic contacts for both n and p-GaAs
using the same contact materials. 相似文献
98.
ZQ Wang T Todani Y Watanabe A Toki Y Sato K Ogura S Yamamoto 《Canadian Metallurgical Quarterly》1998,13(5-6):414-415
Esophageal hiatal hernias (EHH) are probably caused by congenital, traumatic, or iatrogenic factors, although the etiology remains unknown. EHHs may develop after abdominal wall closure for omphalocele or gastroschisis due to the increased intra-abdominal pressure, however, there have been few reports in the literature. We present a case of EHH developing after abdominal wall closure. 相似文献
99.
H Ogura PJ Offner D Saitoh BS Jordan AA Johnson BA Pruitt WG Cioffi 《Canadian Metallurgical Quarterly》1994,129(12):1233-1239
OBJECTIVE: To evaluate the pulmonary effect of treatment with N-nitro-L-arginine methyl ester (NAME) with and without inhaled nitric oxide (NO) in a swine model of endotoxemia. DESIGN: Randomized controlled trial. SETTING: Laboratory. INTERVENTIONS: Following a 20-minute intravenous infusion of Escherichia coli lipopolysaccharide (LPS) (200 micrograms/kg), animals were resuscitated with saline solution (1 mL/kg per minute) and observed for 3 hours while mechanically ventilated (fraction of inspired oxygen [FIO2], 0.6; tidal volume, 12 mL/kg; positive end-expiratory pressure, 5 cm H2O). Group 1 (LPS, n = 6) received no additional treatment; group 2 (NAME, n = 5) received NAME (3 mg/kg per hour) for the last 2 hours; group 3 (NO, n = 6) received NAME (3 mg/kg per hour) and inhaled NO (40 ppm) for the last 2 hours; and group 4 (control, n = 5) received only saline solution without LPS. MAIN OUTCOME MEASURES: Cardiopulmonary variables and blood gases were measured serially. The multiple inert gas elimination technique was performed at 3 hours. The wet-to-dry lung weight ratio was measured following necropsy. RESULTS: Administration of LPS resulted in pulmonary arterial hypertension, pulmonary edema, and hypoxemia with increased ventilation perfusion ratio mismatching. None of these changes were attenuated by NAME treatment alone but all were significantly improved by the simultaneous administration of inhaled NO. CONCLUSIONS: Systemic NO synthase inhibition failed to restore hypoxic pulmonary vasoconstriction following LPS administration. The deleterious effects of endotoxemia on pulmonary function can be improved by inhaled NO but not by systemic inhibition of NO synthase. 相似文献
100.
A Ogura O Suzuki K Tanemura K Mochida Y Kobayashi J Matsuda 《Canadian Metallurgical Quarterly》1998,95(10):5611-5615
Primary spermatocytes are the male germ cells before meiosis I. To examine whether these 4n diploid cells are genetically competent to fertilize oocytes and support full embryo development, we introduced the nuclei of pachytene/diplotene spermatocytes into oocytes that were arrested in prophase I (germinal vesicle stage), metaphase I, or metaphase II (Met II). Both the paternal and maternal chromosomes then were allowed to undergo meiosis synchronously until Met II. In the first and second groups, the paternal and maternal chromosomes had intermingled to form a large Met II plate, which was then transferred into a fresh enucleated Met II oocyte. In the third group, the paternal Met II chromosomes were obtained by transferring spermatocyte nuclei into Met II oocytes twice. After activation of the Met II oocytes that were produced, those microfertilized at metaphase I showed the best developmental ability in vitro, and three of these embryos developed into full-term offspring after embryo transfer. Two pups (one male and one female) were proven to be fertile. This finding provides direct evidence that the nuclei of male germ cells acquire the ability to fertilize oocytes before the first meiotic division. 相似文献