Browsing by Issue Date, starting with "1994-09-15"

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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
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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
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電子物理學系
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光電工程學系
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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
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交大名義發表
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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.
THERMAL-STABILITY OF CU/COSI2 CONTACTED P+N SHALLOW JUNCTION WITH AND WITHOUT TIW DIFFUSION BARRIER
(1994-10-01)
CHIOU, JC
;
CHEN, MC
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The thermal stability of Cu/CoSi2 contacted p+n shallow junction diodes with and without TiW diffusion barrier was investigated with respect to metallurgical reaction and electrical characteristics. Without the diffusion barrier, the Cu (2000 angstrom)/CoSi2 (700 angstrom)/p+n diodes (with a junction depth of 0.2 mum measured from the silicide surface) were able to sustain a 30 s rapid thermal annealing (RTA) in N2 ambient up to 450-degrees-C without losing the integrity of the devices characteristics. The Cu3Si phase was observed at the CoSi2/Si interface after 500-degrees-C annealing; the phase penetrated through the CoSi2 layer causing a catastrophic change in layer structure after 700-degrees-C annealing. With the addition of a 1200 angstrom thickness of TiW diffusion barrier between Cu and CoSi2, the junction diodes were able to sustain the RTA treatment up to 775-degrees-C without degrading the basic electrical characteristics, and no metallurgical reaction could be observed even after an 800-degrees-C annealing.
THE COMBINED EFFECTS OF LOW-PRESSURE NH3-ANNEALING AND H-2 PLASMA HYDROGENATION ON POLYSILICON THIN-FILM TRANSISTORS
(1994-10-01)
YANG, CK
;
LEI, TF
;
LEE, CL
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The low pressure NH3-annealing and the H-2. plasma hydrogenation were jointly used to improve the characteristics of polysilicon thin-film transistors (TFT's). It was found that the TFT's after applying the above treatments achieved better subthreshold swings, threshold voltages, field effect mobilities, off currents, and reliability. It is believed that the improvement was due to the gate oxynitride formation and the H-2-plasma had a better passivation effect on the oxynitride.
AUTOMATIC FORM FEATURE RECOGNITION AND 3D PART RECONSTRUCTION FROM 2D CAD DATA
(1994-10-01)
LIU, CH
;
PERNG, DB
;
CHENZ
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資訊科學與工程研究所
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工業工程與管理學系
In this paper, a method which can recognize form features and reconstruct 3D part from 2D CAD data automatically is proposed. First, we use the divide-and-conquer strategy to extract the vertex-edge data from each 2D engineering drawing of IGES format. Then, a set of production rules are developed to facilitate the form feature matching process. A new structure of form feature adjacency graph (FFAG) is devised to record the related attributes of each form feature. Finally, to avoid the combinatorial subparts-composition problem, a sweeping operation and volumetric intersection approach is used to rapidly reconstruct the remaining 3D object. The last reconstructed 3D object is used as the base of the FFAG. All the recognized form features in the FFAG can be classified as depression or protrusion features on the 3D part base. The FFAG structure can be easily transformed into CSG/DSG structure, which is readily integrated with the downstream CAPP/CAM systems. A detailed example is provided to illustrate the feasibility and effectiveness of the proposed system.
GROWTH, SELF-RANDOMIZATION, AND PROPAGATION IN A LORENTZ LATTICE-GAS
(1994-10-01)
MENG, HF
;
COHEN, EGD
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物理研究所
;
Institute of Physics
A systematic study is carried out of a Lorentz lattice gas in order to model the growth dynamics of order-disorder interfaces. In the model, a particle, initially at the origin, moves on the bonds of an initially ordered square lattice, with sites covered by periodically repeated square blocks of 1, 4, or 9 right or left scattering rotators, whose orientations change after collisions with the particle. Depending then on the initial conditions of the blocks and the particle, one observes the following: (a) the particle randomizes the rotator orientations completely, in an ever growing disordered ''liquid'' phase inside the ordered ''solid'' phase on the rest of the lattice; (b) the particle propagates suddenly after a transient randomization period as in (a); or (c) the particle propagates through the ordered lattice immediately. A simple picture for the growth of the randomized region, which proceeds via an interface of fractal dimension 0.75, is discussed. The nature of the propagation for the cases mentioned can be modified by collisions with impurities.
WDM CODING SYSTEM WITH SINGLE PARITY-CHECK CHANNEL
(1994-10-01)
KAO, MS
;
SHAO, SK
;
CHEN, HY
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電信工程研究所
;
電信研究中心
We propose a modified WDM coding system with a single parity-check channel to achieve an efficient and flexible WDM coding system. The system provides most of the advantages of the original WDM coding system with just one parity-check channel. The bit rate and the data sequences are unaffected by the coding processes, making it very attractive for practical lightwave systems with standard rates. Compared to serial coding systems, it is able to reduce the number of encoding/decoding pairs in an m-channel WDM transmission system operated at STS-N from m x N to one. We have evaluated the system performance and analyzed the performance of frame synchronization needed for the modified WDM coding system. An example shows that the WDM coding can reduce the error floor of a four-channel dispersion-limited WDM system from 10(-10) to 10(-19) with reliable frame synchronization.