Browsing by Author "WU, SC"

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COMPOSITIONAL DEPENDENCE OF THERMAL-STABILITY OF REFRACTORY-METAL SILICIDE SCHOTTKY CONTACTS TO GAAS
(1989-09-01)
LEE, CP
;
LIU, TH
;
WU, SC
;
奈米中心
;
Nano Facility Center
COPPER VALENCY OF SUPERCONDUCTING PHASES IN THE PB-DOPED BI-SR-CA-CU-O SYSTEM
(1992-07-01)
CHEN, FH
;
KOO, HS
;
WU, SC
;
TSENG, TY
;
HORNG, SR
Pb-doped Bi-Sr-Ca-Cu high-T(c) superconducting oxides have been prepared by a modified sol-gel process via the EDTA route. Upon decomposing the X-ray photoemission spectrum of the Cu 2p3/2 core level of the superconducting oxide into three components Cu1+, Cu2+ and Cu3+, we have found an obvious trend: the corresponding [Cu1+]/[Cu2+] ratio increased as more 110 K phase was formed in the sample. According to this trend, a defect model was proposed; it can reasonably explain some previous experimental results, such as a reduced oxygen atmosphere sintering, which effectively facilitates the formation of the 110 K phase, and the coexistence of copper and oxygen vacancies in Bi-system superconductors, observed by high-resolution transmission electron microscopy. On the other hand, the dimerization of holes in oxygen sites was also suggested to be a possible mechanism responsible for the increase in the ratio of [Cu1+]/[Cu2+].
DOUBLE RESONANT BEHAVIOR OF MICROSTRIP RING-RESONATOR IN TL-BASED HIGH T-C SUPERCONDUCTING FILMS
(1994-12-19)
WU, SC
;
YEH, CY
;
CHEN, FH
;
TSENG, TY
;
WANG, C
GROWTH PARAMETER EFFECT IN SUPERCONDUCTING YBA2CU4O8 THIN-FILMS BY DC MAGNETRON SPUTTERING
(1994-11-01)
WU, SC
;
HSU, HT
;
CHEN, FH
;
CHANG, WR
;
TSENG, TY
High-T-c YBa2Cu4O8 (124) thin films have been made by d.c. magnetron sputtering deposition on (100) MgO substrates. The effect of several processing variables, including the ratio of oxygen to argon, total pressure, and substrate temperature, on the superconducting properties of the thin films, were systematically investigated. The as-prepared films annealed in flowing oxygen at 800 degrees C for 4 h under ambient pressure obtained nearly phase-pure 124 and exhibited superconducting onset transition at 75 K.
MOLYBDENUM SILICIDE SCHOTTKY CONTACTS TO GAAS
(1991-03-01)
CHUANG, HF
;
LEE, CP
;
WU, SC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The thermal stability of MoSi(x) Schottky contacts to GaAs has been studied. The contacts were analysed by Rutherford backscattering spectroscopy (RBS), X-ray diffraction (XRD), sheet resistance, and current-voltage measurements. We have studied MoSi(x) with the compositions x = 0, 0.3, 0.6, 1, and 2. The films were annealed at various temperatures up to 850-degrees-C. The thermal stability of the films is found to be x-dependent. The best composition for thermally stable Schottky contacts is Mo5Si3. Good Schottky characteristics were retained with annealing temperatures up to 850-degrees-C for 30 min.
PRESSURE EFFECT ON YBA2CU3O7 THIN-FILM GROWTH IN OFF-AXIS RADIO-FREQUENCY MAGNETRON SPUTTERING
(1995-09-01)
WU, SC
;
TSAI, WC
;
HUANG, CK
;
HSU, HT
;
HUANG, CJ
YBa2CU3O7-x (123) thin films were fabricated on (100) MgO substrates by off-axis single target radio frequency (rf) magnetron sputtering. Our study focused on the effect of chamber pressure on the composition, microstructure, and superconductive properties on transition behavior and T-c, of the grown him studied. An empirical formula was derived to explain the dependence of the deposition rate of various components on the pressure. Next, we compared the transport mechanism of the sputtered particles between the off-axis rf and the on-axis direct current sputtering and determined the processing conditions that result in superconducting films of better quality. According to our findings, growth at higher pressures (>100 mTorr) produces more homogeneous and higher T-c superconducting films. (C) 1995 American Vacuum Society.
TANTALUM SILICIDE SCHOTTKY CONTACTS TO GAAS
(1989-01-15)
LEE, CP
;
LIU, TH
;
LEI, TF
;
WU, SC
;
奈米中心