Browsing by Issue Date, starting with "1995-09-01"

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CHARACTERIZATION OF THE CHEMICAL-MECHANICAL POLISHING PROCESS-BASED ON NANOINDENTATION MEASUREMENT OF DIELECTRIC FILMS
(1995-09-01)
LIU, CW
;
DAI, BT
;
YEH, CF
;
電子工程學系及電子研究所
;
奈米中心
To better understand variations in the rate at which material is removed from a wafer during chemical-mechanical polishing (CMP), knowledge of the mechanical properties of the wafer surface is required. The nanoscale mechanical. properties of undoped dielectric films were investigated using the nanoindentation technique. Crack resistance examined from the loading curve suggested that precursor cracks for SiH4-atmospheric pressure chemical deposition films with a tensile stress, as compared with other dielectric films with compressive stresses, appeared in the earlier stage of indentation. The hardness of dielectric films determined from the unloading curve could be considerably dependent on the film's preparation methods. Correlation between the Si-O bond densities and hardness were also studied. Experimental results showed that there was a Linear relationship between the surface hardness and the removal rates of the undoped dielectric films under a well-controlled CMP process.
RECOGNITION OF RICKER WAVELETS BY SYNTACTIC ANALYSIS
(1995-09-01)
HUANG, KY
;
LEU, DR
;
資訊工程學系
;
Department of Computer Science
Syntactic pattern recognition techniques are applied to the analysis of 1-D seismic traces to classify picker wavelets. Seismic picker wavelets have structural information, and each wavelet can be represented by a string of symbols. To recognize the strings, we use a finite-state automaton to identify each string. The automaton can accept strings having substitution, insertion, and deletion errors of the symbols. There are two attributes, terminal symbol and weight, in each transition of the automaton. A minimum-cost, error-correcting, finite-state automaton is proposed to parse the input string.
INVESTIGATION OF A HIGH-QUALITY AND ULTRAVIOLET-LIGHT TRANSPARENT PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION SILICON-NITRIDE FILM FOR NONVOLATILE MEMORY APPLICATION
(1995-09-01)
WANG, CK
;
YING, TL
;
WEI, CS
;
LIU, LM
;
電子工程學系及電子研究所
A high quality and ultraviolet-light transparent (UV-transparent) plasma enhanced chemical vapor deposition (PECVD) silicon nitride (SiNz) film is developed to form passivation layer for non-volatile memory devices. Comparing to the conventional PECVD SiNx film known to have tensile stress and opacity to ultraviolet-light (UV-light), the proposed SiNz film with very low compressive stress (<1x10(9) dyn/cm(2)) and excellent UV-transmittance (>70% for 1.6 mu m-thick film) can be achieved. The film stress is strongly related to RF input power during deposition process. The UV-transmittance is influenced by pressure and SiH4/NH3 flow ratio. It is also shown that the UV-transmittance is closely correlated to refractive index (RI), film density as well as N/Si ratio inside the film. This SiNx film has been successfully applied to erasable programming read-only memory (EPROM's) devices, and very good UV-erasability and reliability performances are demonstrated.
IDENTIFYING UNTESTABLE FAULTS IN SEQUENTIAL-CIRCUITS
(1995-09-01)
LIANG, HC
;
LEE, CL
;
CHEN, JE
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This article proposes an efficient method to identify untestable faults in sequential circuits. It uses a controllability calculation and symbolic simulation procedure that propagates the characteristics of unknown initial flip-flop states throughout the circuit. Identifying flip-flops that cannot be initialized and circuit lines that cannot be justified to definite values, this process classifies and identifies four types of untestable faults. Experimental results show that it improves the efficiency of a test generation system.
L(P) NORM BACK-PROPAGATION ALGORITHM FOR ADAPTIVE EQUALIZATION
(1995-09-01)
SIU, S
;
CHANG, CH
;
WEI, CH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The l(p) norm back propagation algorithm for perceptron based adaptive equalization is analyzed taking account of possible numerical problem encountered when p < 1. Two methods are proposed to overcome the numerical problem. Computer simulations indicate that simultaneous improvement in convergence rate and bit-error-rate (BER) performance can be achieved by using p < 2.
FRACTURE-TOUGHNESS OF ACRYLONITRILE-BUTADIENE-STYRENE BY J-INTEGRAL METHODS
(1995-09-01)
LU, ML
;
LEE, CB
;
CHANG, FC
;
應用化學系
;
Department of Applied Chemistry
The fracture toughness of acrylonitrile-butadiene-styrene (ABS) was determined by three J-integral methods, ASTM E813-81, E813-87, and by hysteresis. The critical J values (J(1c)) obtained are fairly independent of the specimen thickness, ranging from 10 to 15 mm. ASTM E813-81 and hysteresis methods result in comparable J(1c) values, whereas the ASTM E813-87 was similar to 40% to 50% higher. The critical displacement determined from the plots of hysteresis (energy or ratio) and the true crack grow length vs. displacement are close. This indicates the critical displacement determined by the hysteresis method is indeed the displacement at onset of crack initiation, and the corresponding J(1c) represents a physical event of crack initiation. The elastic storage energy, the input energy minus the hysteresis energy, is the most important factor in determining the onset of crack initiation. The critical elastic storage energy (at the beginning of crack growth) was found close to the J(1c) obtained from the E813-81 or the hysteresis method.
L(P) NORM BACK-PROPAGATION ALGORITHM FOR ADAPTIVE EQUALIZATION
(1995-09-01)
SIU, S
;
CHANG, CH
;
WEI, CH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The l(p) norm back propagation algorithm for perceptron based adaptive equalization is analyzed taking account of possible numerical problem encountered when p < 1. Two methods are proposed to overcome the numerical problem. Computer simulations indicate that simultaneous improvement in convergence rate and bit-error-rate (BER) performance can be achieved by using p < 2.
MULTIBAND WAVELENGTH-DIVISION DEMULTIPLEXING WITH A CASCADED SUBSTRATE-MODE GRATING STRUCTURE
(1995-09-01)
TSAI, YK
;
HUANG, YT
;
SU, DC
;
電子工程學系及電子研究所
;
光電工程研究所
A multiband wavelength-division-demultiplexing (WDDM) structure, which incorporates cascaded substrate-mode holograms, is presented. The method can be used to design a WDDM device that consists of two or more layers of fundamental units (i.e., substrate-mode holograms). The fundamental unit is based on a diffracted grating and a substrate that include angular dispersion, wavelength bandwidth, and total internal reflection, which can be used to separate optical signals of different wavelengths. We have designed and built a multiband WDDM device, incorporating cascaded substrate-mode holograms in dichromated gelatin.
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.
Impact analysis of shear deformable laminated composite plates
(1995-09-01)
Kam, TY
;
Chang, WJ
;
機械工程學系
;
Department of Mechanical Engineering
A method for investigating the dynamic response of shear deformable laminated composite plates subject to low-speed impact is presented. The equations of motion of the impactor and the plate are derived via a virtual work approach. The contact force between the impactor and the plate is calculated by using an experimentally established contact law. The effects of existing in-plane forces, plate aspect ratio, length-to-thickness ratio, fiber angles, and number of layer groups on the contact force with or without the consideration of ply failure are studied. Optimal fiber angles and number of layer groups for angle-ply plates with maximum first-ply failure impact velocity are determined based on the maximum stress criterion.
Failure restoration of mobility databases for personal communication networks
(1995-09-01)
Lin, Yi-Bing
;
資訊工程學系
;
資訊科學與工程研究所
;
Department of Computer Science
;
Institute of Computer Science and Engineering
This paper studies failure restoration of mobility databases for personal communication networks (specifically, VLRs and HLRs). We model the VLR restoration with and without checkpointing. The optimal VLR checkpointing interval is derived to balance the checkpointing cost against the paging cost. We also model GSM periodic location updating (location confirmation) to quantify the relationship between the location confirmation frequency and the number of lost calls. The HLR failure restoration procedures for IS-41 and GSM are described. We show the number of lost calls in a HLR failure. Both the procedures in IS-41 and GSM cannot identify the VLRs that need to be accessed by the HLR after a failure. An algorithm is proposed to identify the VLRs, which can be used to aggressively restore a HLR after its failure.
EFFECTS OF SUBSTRATE-TEMPERATURE AND OXYGEN PARTIAL-PRESSURE ON THE PROPERTIES OF SPUTTERED ZIRCONIUM TITANATE THIN-FILMS
(1995-09-01)
CHANG, DA
;
LIN, P
;
TSENG, TY
;
材料科學與工程學系
;
電子工程學系及電子研究所
We report the effects of substrate temperature and O-2/Ar ratios on the properties of ZrTiO4 thin films prepared by RF magnetron sputtering. The films were deposited at a constant gas pressure (0.133 Pa) with various substrate temperatures (25-450 degrees C) and different O-2/Ar ratios from 0/100 to 20/80. The deposition rate decreases with increasing oxygen partial pressure and substrate temperature. Moreover, the higher O-2 content increases the surface roughness of deposited films, which reduces the transmittance of the films. The effects of substrate temperature and oxygen partial pressure on the stoichiometric composition, optical constant, crystallinity phase, surface morphology, and adhesion have also been systematically investigated.
A MODIFIED CRITERION FOR OUTPUT-FEEDBACK TRACKING PROBLEMS WITH DETERMINISTIC AND STOCHASTIC SIGNALS
(1995-09-01)
HWANG, MS
;
LEE, FC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A modified criterion for designing a linear time-invariant controller for an output feedback tracking problem is studied. This criterion takes the responses due to stochastic and deterministic signals into account. The advantage of this criterion is in its design potentiality to take care of both performances due to stochastic and deterministic signals in a time-invariant controller. Theoretical properties of this criterion include existence, uniqueness and closed-loop stability of the optimal solution. Moreover, this solution satisfies a separation property and incorporates a required internal model for the tracking requirement.
OBSERVER SYNTHESIS OF NONLINEAR INTERCONNECTED SYSTEMS BY CONSTRAINED RICCATI APPROACH
(1995-09-01)
CHENG, CF
;
WANG, WJ
;
LIN, YP
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper provides a method for observer synthesis of interconnected systems with nonlinearities in subsystems and interconnection terms, which satisfy the Lipschitz-type conditions instead of any matching conditions. A new observer scheme is proposed under a local observability assumption, and the respective observer gains are obtained through Riccati equations with linear constraints. Solvability conditions for such a Constrained Riccati Problem (CRP) are derived, and a systematic procedure for obtaining the solution of a constrained Riccati equation is presented. Furthermore, the relationship between tolerable Lipschitz constants of the modeling nonlinearities and observer gains is established.
Impact analysis of shear deformable laminated composite plates
(1995-09-01)
Kam, TY
;
Chang, WJ
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
A method for investigating the dynamic response of shear deformable laminated composite plates subject to low-speed impact is presented. The equations of motion of the impactor and the plate are derived via a virtual work approach. The contact force between the impactor and the plate is calculated by using an experimentally established contact law. The effects of existing in-plane forces, plate aspect ratio, length-to-thickness ratio, fiber angles, and number of layer groups on the contact force with or without the consideration of ply failure are studied. Optimal fiber angles and number of layer groups for angle-ply plates with maximum first-ply failure impact velocity are determined based on the maximum stress criterion.
An approximate agreement algorithm for wraparound meshes
(1995-09-01)
Cheng, RL
;
Chung, CP
;
交大名義發表
;
資訊科學與工程研究所
;
National Chiao Tung University
An appropriate algorithm, the neighboring exchange, for reaching an approximate agreement in a wraparound mesh is proposed. The algorithm is characterized by its isotropic nature, which is of particular usefulness when applied in any symmetric system. The behavior of this algorithm can be depicted by recurrence relations which can be used to derive the convergence rate. The convergence rate is meaningful when the algorithm is used to synchnize clocks. The rate of synchronizing clocks is derived, and it can be applied to all wraparound meshes with practical scale. With the recurrence relations, we also prove the correctness of this algorithm.
EVALUATION OF NI-IN-NI MULTILAYERS FOR THERMALLY STABLE OHMIC CONTACTS TO N-GAAS
(1995-09-01)
HSIA, ST
;
LEE, CP
;
HWANG, HL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A thermally stable, low resistance ohmic contact system Ni-Ln-Ni to n-GaAs was investigated. The lowest value of the specific contact resistance rho(c) was 1.71 x 10(-4) Omega cm(2). Hearing the contact up to 400 degrees C for 5 h did not obviously change the value of rho(c). It was observed by Auger electron spectroscopy and X-ray diffraction that Ni-Ln compounds, Ga-Ni and InAs formed at the metal-GaAs interface. It was noted that In reacted with GaAs and formed a heterojunction ohmic contact (such as InAs-InxGa1-xAs-GaAs) and due to the low melting point (156 degrees C) of In, additions of Ni are needed to completely react the remaining In to form a high melting point compound.
DEPENDENCE OF ELECTRON-MOBILITY ON DOPED IMPURITIES
(1995-09-01)
CHEN, YF
;
KWEI, CM
;
SU, P
;
TUNG, CJ
;
電子工程學系及電子研究所
The dependence of electron mobility on doped impurities was investigated. Analytical expressions of the momentum relaxation cross section and the electron mobility in n- and p-doped silicon for electron-impurity scatterings have been derived. Our approach involved the application of a screened scattering potential based on a charge density distribution for impurity ions in the semiconductor. This distribution was determined by the variational statistical method. Calculated results showed that ionized acceptor impurities in silicon scattered electron carriers less strongly than did ionized donor impurities. They also showed that majority electron mobility in n-type silicon was less than minority electron mobility in p-type silicon. These were consistent with experimental observations.
ALGAAS/GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS ON SI SUBSTRATE USING EPITAXIAL LIFT-OFF
(1995-09-01)
FAN, JC
;
LEE, CP
;
HWANG, JA
;
HWANG, JH
;
電子工程學系及電子研究所
Epitaxial lift-off (ELO) technique was used for the first time to transplant AlGaAs/GaAs Heterojunction Bipolar Transistors (HBT's) to Si substrates. Both preprocessed (devices processed before transplantation) and postprocessed (devices processed after transplantation) ELO HBT's On Si were demonstrated in this study. The characteristics of those HBT's on Si with either technique show nearly identical characteristics of the HBT's on GaAs without transplantation, indicating the film quality is maintained after transplantation. Devices with a high current gain of 550 were transplanted without any degradation, and the current gain is not limited by the ELO process. This current gain value is the highest reported for GaAs HBT's on Si with any techniques.
LINK ENHANCEMENT USING CONSTRAINED RANGE AND REDUCED CANDIDATE SET SEARCHES - A REVISION
(1995-09-01)
LIN, RY
;
YANG, CY
;
管理科學系
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Management Science
This paper revises the CRCS algorithm proposed by Yang(1). In the constrained range search, we use the cost and performance of candidate links to obtain the exact link range of the optimal solution. Moreover, we use the concept of variable dominance to reduce the number of candidate links without loss of optimality. A comparison of results obtained using Yang's and the revised CRCS algorithm shows that the revised CRCS algorithm is superior to Yang's original version.