Browsing by Issue Date, starting with "1994-09-10"

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子子孫孫孫子子孫孫孫子子
(1994-09-10)
管管
子子孫孫孫子子孫孫孫子子
(1994-09-10)
管管
子子孫孫孫子子孫孫孫子子
(1994-09-10)
管管
子子孫孫孫子子孫孫孫子子
(1994-09-10)
管管
ENHANCED DIAMAGNETISM IN YBA2CU3O7-DELTA BY HYDROGEN-PLASMA TREATMENT
(1994-09-10)
LEE, MW
;
TAI, MF
;
LEE, HJ
;
HWANG, HL
;
KAO, HCI
We report that the diamagnetism of as-grown YBa2Cu3O7-delta powders can be enhanced by treatment with RF-generated hydrogen plasma. The field-cooling susceptibility at 5 K is found to increase by up to 24%. The enhancement is reproducible for all five samples studied. The lattice parameter c decreases after hydrogenation. For a sample treated for the shortest period, its pinning potential, obtained from magnetic relaxation measurements, is reduced following H-treatment.
2H PHASE IN A CU2MNAL ALLOY
(1994-09-15)
JENG, SC
;
LIU, TF
;
交大名義發表
;
材料科學與工程學系
;
National Chiao Tung University
FORMATION OF SHALLOW P(+)N JUNCTIONS BY BF2+ IMPLANTATION INTO THIN POLYCRYSTALLINE SI FILMS
(1994-09-15)
LIN, CT
;
JUANG, MH
;
JAN, ST
;
CHOU, PF
;
CHENG, HC
Excellent shallow p(+)n junctions have been formed by implanting BF2+ ions into thin polycrystalline Si films and subsequent annealing. The samples implanted with 5X10(15) cm(-2) at 50 keV show a leakage of 1 nA/cm(2) and a junction depth of about 0.05 mu m after a 800 degrees C annealing. Various implant and annealing cases were examined to determine and characterize their effects on the resultant junctions. High energy implantations (125 and 150 keV) exhibit poor characteristics at all annealing temperatures because the Si substrates are severely damaged. However, the specimens implanted below 100 keV result in excellent diode characteristics for all implantation doses after an 800 degrees C annealing since the implantation defects are confined in the poly-Si layer. The major factors affecting the junction depth were found to be the implantation energy and annealing temperature, while a minor for the implantation dosage. Furthermore, the effects of the subsequent silicidation on the resultant junction characteristics were also investigated.
EDGE DOMINATION IN COMPLETE PARTITE GRAPHS
(1994-09-15)
CHEN, BL
;
FU, HL
;
應用數學系
;
Department of Applied Mathematics
An edge dominating set in a graph G is a set of edges D such that every edge not in D is adjacent to an edge of D. An edge domatic partition of a graph G = (V, E) is a collection of pairwise-disjoint edge dominating sets of G whose union is E. The maximum size of an edge domatic partition of G is called the edge domatic number. In this paper, we study the edge domatic number of the complete partite graphs and give the answers for balanced complete partite graphs and complete split graphs.
DUAL-WAVELENGTH ACTIVELY MODE-LOCKED LASER-DIODE ARRAY WITH AN EXTERNAL GRATING-LOADED CAVITY
(1994-09-15)
WANG, CL
;
PAN, CL
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
We report the generation of dual-wavelength picosecond pulses by use of a commercial laser-diode array. The laser cavity incorporated a folded dispersive delay line with a V-shaped double-stripe mirror. The spectral separation of the laser output at the two wavelengths can be tuned from 2 to 11 nm. The actively mode-locked pulse widths at the two wavelengths were both 29 ps. Cross-correlation and power-spectrum measurements indicated that the two-color pulses were synchronized with an absolute timing jitter of less than 1 ps (instrument limited).
LOW-TEMPERATURE DIAMOND GROWTH AND PLASMA SPECIES ANALYSIS USING METHANE-CARBON DIOXIDE GAS-MIXTURES
(1994-09-15)
CHEN, CF
;
CHEN, SH
;
HONG, TM
;
WANG, DP
;
材料科學與工程學系
GRAIN-GROWTH OF LASER-RECRYSTALLIZED POLYCRYSTALLINE AND AMORPHOUS-SILICON FILMS
(1994-09-15)
TSAI, MJ
;
CHENG, HC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The grain growth mechanisms of polycrystalline and amorphous silicon films on SiO2 have been studied using continuous wave (CW) CO2 laser system under different laser powers. A solid-phase grain growth mechanism was observed at laser powers ranging from 5 W to 15 W. In this power region, the grain growth of the amorphous silicon specimens was more significant than that of the polycrystalline silicon ones. Dramatic grain growth was obtained as the laser power increased from 17.5 W to 22.5 W for both specimens. The liquid-phase grain growth mechanism could be used to explain this phenomenon. In the solid-phase grain growth regime, the [110] texture was dominant for the polycrystalline silicon samples and a stronger [100] texture was observed for the amorphous specimens. However, X-ray diffraction revealed a [100] preferred orientation for both the laser-recrystallized polycrystalline and amorphous silicon films in liquid-phase growth regime. Furthermore, thin film transistors fabricated with these recrystallized films were also demonstrated. TFTs with an on/off current ratio of 1.58 x 10(8) and an effective mobility as large as 200 cm(2) V-1 s(-1) could be achieved for silicon films laser-recrystallized in the liquid-phase growth regime due to the large grain size.
CATHODOLUMINESCENT CHARACTERISTICS OF ZNGA2O4 PHOSPHOR GROWN BY RADIO-FREQUENCY MAGNETRON SPUTTERING
(1994-09-15)
HSIEH, IJ
;
CHU, KT
;
YU, CF
;
FENG, MS
;
材料科學與工程學系
Low voltage cathodoluminescent characteristics of ZnGa2O4 phosphor grown by rf magnetron sputtering have been investigated from 300 to 700 nm. The effects of substrate heating and annealing treatment on the luminescent characteristics are also studied. A blue cathodoluminescent emission peaked at 470 nm is observed. Better luminescent properties are achieved on the films which have crystal structure with a standard powder x-ray diffraction pattern of ZnGa2O4. The effect of the strength of the ligand field on the resultant energy levels for the ZnGa2O4 phosphor is investigated. Low-voltage phosphor films with excellent cathodoluminescent characteristics have been successfully developed in this research.
ULTRASHORT SOLITON PULSE-TRAIN PROPAGATION IN ERBIUM-DOPED FIBER AMPLIFIERS
(1994-09-15)
CHI, S
;
CHANG, CW
;
WEN, SF
;
光電工程學系
;
Department of Photonics
A theoretical model for the transmission of ultrashort soliton pulse trains in erbium-doped fiber amplifiers is developed. The model is used to study nonreciprocal characteristics of energy amplification and the evolution of the pulse train in a doped fiber with different pumping configurations.
PROPERTIES OF PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITED A-SINX-H BY VARIOUS DILUTION GASES
(1994-09-15)
HSIEH, SW
;
CHANG, CY
;
LEE, YS
;
LIN, CW
;
HSU, SC
The effects of dilution gases on hydrogenated amorphous silicon nitride (a-SiNx:H) films were investigated. Silane and ammonia were used as the reactive species, while nitrogen, helium, hydrogen, and argon were used as the-dilution gases in a plasma-enhanced chemical vapor-deposition system at a substrate temperature of 300 degrees C. The electrical, physical, and chemical properties of the a-SiNx:H films were found to be highly sensitive to the various kinds and flow rates of the carrier gases in the deposition. Additionally, the physical properties of growth rate, refractive index, and etching rate were also investigated. The hydrogen bonding configuration was explored by infrared spectroscopy. The total hydrogen concentrations for all a-SiNx:H films were observed to be smaller than 3.0X 10(22) cm-(3). The electrical properties were characterized by I-V and C-V measurements in metal-insulator-semiconductor structures. The breakdown strength was determined at the current density of 3 mA/cm(2); in addition, the dominant mode of electronic conduction would appear to be the Poole-Frenkel emission. The interface trap state density D-it which ranged from 3.4X10(11) to 1.3X10(12) cm(-2) eV(-1) was evaluated by the C-V characteristics. Finally, the influences of the gas dilution in the alpha-SiNx:H films, as applied to the devices, were investigated by using the hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs). Analyses of the transfer characteristics of the TFT devices revealed that the density of deep gap states is 4x10(12) cm(-2) eV(-1) and the field-effect mobility mu(FE) is changing from 0.37 to 1.45 cm(2)/V s.
OPTIMAL BORESIGHT ERROR DESIGN OF RADOMES OF REVOLVING SYMMETRY
(1994-09-15)
HSU, F
;
CHAN, KK
;
CHANG, PR
;
CHAO, SH
;
電信工程研究所
An optimisation technique is applied to the design of three-dimensional radomes of revolving symmetry. A design example for an ogive radome is given. The best possible thickness profile of the radome is found and the boresight error is reduced significantly. Both B-spline modelling and polynomial modelling for the thickness profile are considered.
SURFACE SUPERCONDUCTIVITY OF SHORT COHERENCE LENGTH SUPERCONDUCTORS
(1994-09-20)
CHEN, JL
;
YANG, TJ
;
電子物理學系
;
光電工程學系
;
Department of Electrophysics
Based on the theory of Valls et al. for short coherence length superconductors, de Gennes' boundary theory for conventional superconductors with xi(0)>>k(F)(-1) may be modified. We solve the G-L equation exactly under zero magnetic field for various temperatures. The order parameter psi(x) is not depleted but enhanced near the surface. We also obtain some interesting results: T-c will be enhanced by contracting of the thickness of a superconducting film. The nucleation field H-c3(T) proportional to (T-cb-T) near T-cb; and H-c3(T)proportional to(T-c-T)(1/2) near T-c. The critical current in SIS Josephson junctions J(c)(T)proportional to(T-c- T) + root 2 tau(0)(T-0-T) for T
SURFACE SUPERCONDUCTIVITY OF SHORT COHERENCE LENGTH SUPERCONDUCTORS
(1994-09-20)
CHEN, JL
;
YANG, TJ
;
電子物理學系
;
光電工程研究所
;
Department of Electrophysics
Based on the theory of Valls et al. for short coherence length superconductors, de Gennes' boundary theory for conventional superconductors with xi(0)>>k(F)(-1) may be modified. We solve the G-L equation exactly under zero magnetic field for various temperatures. The order parameter psi(x) is not depleted but enhanced near the surface. We also obtain some interesting results: T-c will be enhanced by contracting of the thickness of a superconducting film. The nucleation field H-c3(T) proportional to (T-cb-T) near T-cb; and H-c3(T)proportional to(T-c-T)(1/2) near T-c. The critical current in SIS Josephson junctions J(c)(T)proportional to(T-c- T) + root 2 tau(0)(T-0-T) for T
DIRECTIONAL SYMMETRY OF THE TIME-LAG FOR DOWNSTREAM ABSORPTIVE PERMEATION STUDIED BY THE MATRIX-METHOD
(1994-09-21)
CHEN, JS
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
;
Department of Applied Chemistry
The directional symmetry of the downstream time lag for absorptive permeation, accompanying a first-order reaction, across a heterogeneous membrane has been proven by the matrix method based on the theory of Siegel. Owing to the heterogeneity the partition coefficient (K), diffusivity (D) and rate constant (k) are all dependent on position. The directional symmetry was first shown for multiple laminates with each laminate having a distinct K, D and k. The transmission matrix of the system is then a sequential product of those of the individual laminates. The proof is for the unit value of the determinant of the transmission matrix for each laminate and, hence, for the whole system. Directional symmetry is thus proven for the heterogeneous membrane, since it can be visualized to be an assembly of an infinite number of infinitely thin, homogeneous laminates.
FABRICATION OF P-CHANNEL POLYCRYSTALLINE SI1-XGEX THIN-FILM TRANSISTORS BY ULTRAHIGH-VACUUM CHEMICAL-VAPOR-DEPOSITION
(1994-09-26)
LIN, HC
;
JUNG, TG
;
LIN, HY
;
CHANG, CY
;
CHEN, LP
In this report, we present a novel approach for fabricating polycrystalline silicon-germanium thin-film transistors at low temperatures (less than or equal to 550 degrees C). A bottom gate configuration is used for this approach, and an i-Si1-xGex/i-Si/p(+)-Si1-yGey multilayer is deposited sequentially on the gate oxide using an ultra-high vacuum chemical vapor deposition technique. The i-Si1-xGex serves as the channel while the i-Si is used as a buffer layer for allowing p(+)-Si1-yGey to be etched selectively on. p-channel thin-film transistors with a held-effect mobility of 13 cm(2)/V s were achieved using this method, which is superior to those grown by low pressure chemical vapor deposition. Our results indicate that the deposition of poly-Si1-xGex/poly-Si multilayer structure would be a promising way for polycrystalline thin-film device applications.
INFLUENCE OF THERMODYNAMIC FACTORS ON GROWTH OF ALAS1-XSBX ALLOYS
(1994-10-01)
CHEN, WK
;
CHIN, MT
;
交大名義發表
;
電子物理學系
;
National Chiao Tung University
Epitaxial layers of AlAs1-xSbx have been prepared by metalorganic vapor phase deposition (MOCVD) in a horizontal, atmospheric-pressure quartz reactor. The influences of the V/III ratio and the input partial pressure of trimethylantimony were systematically studied. The experimental results are in good agreement with the calculated ones, based on thermodynamic considerations, which implies that the growth of AlAsSb in MOCVD is controlled predominantly by thermodynamics.