Browsing by Author "Liu, CC"

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10 GHz quadrature-phase voltage controlled oscillator and prescaler
(2003)
Chen, WZ
;
Kuo, CL
;
Liu, CC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a 10 GHz quadrature phase LC-VCO with a novel ring-array based injection-locked prescaler are presented. Fabricated in a 0.18 mum digital CMOS process, output frequency of VCO ranges from 10.03-9.35 GHz, and the prescaler performs divide-by 8 operation with locking range of 1 GHz. The measured phase noise from a 9.395 GHz carrier is -120 dBc/Hz at 5 MHz offset. Operating under a single 1.8 V supply, the VCO and prescaler respectively consume 21.6 mW and 12.6 mW only. Chip size are 1682.8 mum x 647.8 mum.
A computational model of form synthesis based on operation description
(2005)
Liu, CC
;
Deng, YS
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應用藝術研究所
;
Institute of Applied Arts
Design process is an evolving process that begins with design requirements and ends with product description. The complexity of this process is beyond our imagination. The study of design processes attempts to externalize intuitive knowledge held by designers in the process, so we will be able to improve the process and develop the product description in an efficiency way, i.e. computational approach. This study aims to explore what knowledge is involved in design process and how this knowledge is used throughout the process, in which industrial designer translates operation description into synthesizing forms to embody designers' operational intent. From a computational perspective, the knowledge concerned in the process of design, such as the representation of operation, the representation of form elements, the rules of form giving, and the rules controlling the synthesis process, is discussed and formalized in a computational design model. The concept of affordance is adopted to assist the transition from operation description of designers' intent to form description of form elements, which is seen as the embodiments of intended operations. Finally, a computational design model is proposed to simulate the integration of different types of design knowledge. The strength of this computational model lies in its ability to propose multiple synthesized form alternatives to stimulate designers' thinking.
A data mining project for solving low-yield situations of semiconductor manufacturing
(2004)
Chen, WC
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Tseng, SS
;
Hsiao, KR
;
Liu, CC
;
資訊工程學系
With huge amount of semiconductor engineering data stored in database and versatile analytical charting and reporting in production and development, the CIM/MES/EDA systems in the most semiconductor manufacturing companies help users to analyze the collected data in order to achieve the goal of yield enhancement. However, the procedures of semiconductor manufacturing are sophisticated and the collected data among these procedures are thus becoming high-dimensional and huge. Currently, some statistical methods, such like K-W test, covariance analysis, regression analysis, etc., have been used to analyze the information summarized from EDA system, and thus generate too many indexes that can not be easily judged and assimilated by engineers. Besides, too many false alarms may be raised and lots of time is required to check the factuality among them. In order to deal with the large amount and high-dimensional data, the data mining technologies are thus used to solve such problems. In this paper, we would like to propose a data mining solution and describe the experiences applying such solutions for discovering the root causes of low-yield situations in a worldwide semiconductor manufacturing company. Also, the situation of applying such mining solution for manufacturing defects detection in semiconductor manufacturing domain will be reviewed Finally, the architecture of a reasonable, reliable and flexible data mining system will be briefly described.
Anomalous electrical performance of nanoscaled interfacial oxides for bonded n-GaAs wafers
(2006-03-13)
Hao, OY
;
Wu, YCS
;
Chiou, HH
;
Liu, CC
;
Cheng, JH
Electrical performance was found to be closely related to the variation of nanosized interface morphology in previous studies. This work investigated in detail the microstructural development of in- and anti-phase bonded interfaces for n-type (100) GaAs wafers treated at 500, 600, 700 and 850 degrees C. The interfacial energy of anti-phase bonding is higher than that of in-phase bonding based on the first-principles calculations. The higher interface energy tends to stabilize the interfacial oxide layer. The continuous interfacial oxide layer observed below 700 degrees C can deteriorate the electrical property due to its insulating property. However, the existence of nanoscaled oxide at anti-phase bonded interfaces can improve the electrical conductivity at 700 degrees C. This is due to the suppression of the evaporation of As atom by the interfacial nanoscaled oxides based on the analysis of autocorrelation function and energy dispersive x-ray spectroscopy. (c) 2006 American Institute of Physics.
Contact characteristics of beveloid gears
(2002-04-01)
Liu, CC
;
Tsay, CB
;
機械工程學系
;
Department of Mechanical Engineering
This study investigates the contact characteristics of beveloid gear pairs with intersected. crossed and parallel axes. Tooth contact analysis (TCA) is performed to examine the meshing and bearing contact of the beveloid gear pairs composed of a pinion and a gear. In addition, the principal directions and curvatures of the pinion and gear surfaces are investigated and the contact ellipses of the mating tooth surfaces are also studied. Numerical illustrative examples are provided to demonstrate the computational results. (C) 2002 Elsevier Science Ltd. All rights reserved.
COSMIC: Geodetic applications in improving earth's gravity model
(2000-03-01)
Chao, BF
;
Pavlis, EC
;
Hwang, CW
;
Liu, CC
;
Shum, CK
The routine GPS tracking data that will be collected for the precise orbit determination of the eight COSMIC spacecraft will contain valuable information about the terrestrial gravity field. Numerical simulations based on current straw-man mission scenarios have shown: (1) For the static model of the gravity field, significant improvement is possible over our present knowledge embodied in the EGM96 model, out to harmonic degree as high as 40. (2) With respect to time-varying gravitational signals, large-scale mass transport processes in the geophysical fluids (e.g., atmosphere and oceans) can be detected or monitored during the mission, providing important global change information. Further sophisticated simulations incorporating more realistic force models will be needed once COSMIC mission scenario and spacecraft design are completely defined.
Deposition of polycrystalline beta-SiC films on Si substrates at room temperature
(1997-01-13)
Cheng, KL
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Cheng, HC
;
Lee, WH
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Lee, CP
;
Liu, CC
Polycrystalline beta-SiC, with grain size up to 1500 Angstrom, has been room-temperature-deposited on Si substrates by electron cyclotron resonance chemical vapor deposition. Microwave power and the hydrogen carrier gas are the key parameters to lower the deposition temperature. According to the results of the cross-sectional transmission electron microscopy, the grain size appeared to be in the same scale as that deposited at 500 degrees C while a large amount of plasma-induced defects were observed in the Si substrate for the room-temperature-deposited samples. Hence, a CH4-plasma treatment prior to the beta-SiC film growth was adopted, forming a SiC-like interfacial layer to suppress the substrate damages. (C) 1997 American Institute of Physics.
Growth of SiC films on Si(100) by electron cyclotron resonance chemical vapor deposition using SiH4/CH4/H-2
(1995-12-01)
Liu, CC
;
Lee, CP
;
Cheng, KL
;
Cheng, HC
;
Yew, TR
SiC films were deposited on Si(100) substrates by electron cyclotron resonance chemical vapor deposition at 500 degrees C using SiH4/CH4/H-2 gas mixtures. The chemical composition and crystalline microstructure were investigated by x-ray photoelectron spectroscopy and cross-sectional transmission electron microscopy, respectively. The film composition and microstructure are correlated to process variables. The deposition mechanism which controls the film characteristics is presented.
Investigation of the electrical properties and reliability of amorphous SiCN
(2004-01-30)
Chen, CW
;
Chang, TC
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Liu, PT
;
Tsai, TM
;
Huang, HC
Amorphous SiCN (a-SiCN) is a candidate for barrier dielectric and has lower dielectric constant (ksimilar to5) relative to the commonly used barrier SiN (ksimilar to7). In this study, we investigate the leaky behavior and barrier characteristics of a-SiCN (k: 4similar to5) doped with different nitrogen concentration. The leaky behavior of a-SiCN is Poole-Frenkel at high electric field. This is similar to SiN. Thermal stability of a-SiCN films is good enough to meet the prescription in back-end-of-line fabrication process. The bias-temperature stress (BTS) test has been conducted on a-SiCN to investigate the barrier ability against copper 15/16penetration. We find that a-SiCN could sustain the stress of electric field up to 4 mV/cm at 150 degreesC. In addition, a-SiCN films with higher nitrogen concentration exhibit better barrier property against copper penetration. The SIMS spectra also have been used to monitor the distributions of copper after different BTS conditions, confirming our inference on leakage mechanism. (C) 2003 Elsevier Science B.V. All rights reserved.
Manufacturing of low-cost enzymatic biosensors using thick film processing
(2005)
Chuang, MC
;
Shen, J
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Dudik, L
;
Liu, CC
;
交大名義發表
Single-use disposable biosensors are of importance in many applications related to health care, patient management, environmental monitoring, food and water quality analysis, personal safety and national security. Enzymatic biosensors using electrochemical detection techniques can be considered a platform technology. This study focuses on the development of high performance enzymatic biosensors based on this platform technology and their manufacturing methods. The applications of thick-film screen printing and inkjet printing techniques to manufacture the single-use, disposable biosensors are feasible and technically attractive. Experimental results will be presented to demonstrate the effectiveness of the printing technologies in the manufacturing of these biosensors with high performance characteristics.
Mathematical model and surface deviation of helipoid gears cut by shaper cutters
(2003-06-01)
Wu, JL
;
Liu, CC
;
Tsay, CB
;
Nagata, S
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機械工程學系
Crossed-axis helical gears and hypoid gears are two conventional crossed-axis power transmission devices. Helipoid gears, a novel gear proposed herein, possess the merits of the crossed-axis helical and hypoid gears. A mathematical model of the proposed helipoid gear cut by shapers is also derived according to the cutting mechanism and the theory of gearing. The investigation shows that the tooth surface varies with the number of teeth of the shaper Computer graphs of the helipoid gear are presented according to the developed gear mathematical model, and the tooth surface deviations due to the number of teeth of the shaper are also investigated.
Mathematical models and contact simulations of concave beveloid gears
(2002-12-01)
Liu, CC
;
Tsay, CB
;
機械工程學系
;
Department of Mechanical Engineering
This study presents two mathematical models of concave beveloid gears ground by Mitome's grinding method and by the novel grinding method proposed by the authors. Based on the developed mathematical models, the contact simulations are performed and the characteristics of concave beveloid gear pairs are investigated. Simulation results indicate that our novel grinding method ameliorates the drawback of Mitome's grinding method by eliminating the transmission error of the helical concave beveloid gear pairs. In contrast to conventional beveloid gear pairs, the gears ground by the proposed novel grinding method not only have larger contact ellipses, but also mesh conjugately with non-parallel axes, although assembly errors exist.
Modal behavior of dominant modes on gyromagnetic asymmetric coupled lines in both leaky and nonradiation regions
(1996)
Fuh, KF
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Tzuang, CKC
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Liu, CC
;
Lin, YC
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電信工程研究所
Polycrystalline beta-SiC film growth on Si by ECR-CVD at 178-500 degrees C
(1996)
Cheng, KL
;
Liu, CC
;
Fu, CM
;
Cheng, HC
;
Lee, C
Positive oxide charge-enhanced read disturb in a localized trapping storage flash memory cell
(2004-03-01)
Tsai, WJ
;
Yeh, CC
;
Zous, NK
;
Liu, CC
;
Cho, SK
Read disturb-induced erase-state threshold voltage instability in a localized trapping storage Flash memory cell with a poly-silicon-oxide-nitride-oxide-silicon (SONOS) structure is investigated and reported. Our results show that positive trapped charge in bottom oxide generated during program/erase (P/E) cycles play a major role. Both gate voltage and drain voltage will accelerate the threshold voltage (V-t) drift. Hot-carrier caused disturb effect is more severe in a shorter gate length device at low temperature. A model of positive charge-assisted electron tunneling into a trapping nitride is proposed. Influence of channel doping on the V-t drift is studied. As the cell is in an "unbiased" storage mode, tunnel detrapping of positive oxide charges is responsible for the threshold voltage shift, which is insensitive to temperature.
Register renaming for x86 superscalar design
(1996)
Liu, CC
;
Shiu, RM
;
Chung, CP
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資訊科學與工程研究所
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Institute of Computer Science and Engineering
Semi-IPNs formed from poly(ethylene glycol monomethyl ether acrylate) and an epoxy thermoset
(1999-02-01)
Lin, MS
;
Liu, CC
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應用化學系
;
Department of Applied Chemistry
Poly(ethylene glycol monomethyl ether acrylate) (PEGMEA) was synthesized from the reaction of poly(ethylene glycol monomethyl ether) (PEGME) with acryloyl chloride. Semi-IPNs based on various weight ratios of diglycidyl ether of bisphenol A (DGEBA)/PEGMEA were prepared, using isophronediamine (IPDA) and 2,2'-azo-bis (isobutyronitrile) (AIBN) as curing agents. The glass transition temperature and exothermic peak shifts were studied with differential scanning calorimetry (DSC). Viscosity changes during semi-IPN formation were measured with a Brookfield viscometer. Dynamic mechanical properties were investigated by rheometric dynamic spectroscopy (RDS). Stress-strain curves were obtained with an Instron tensile tester, while impact resistance was measured with a computer aided falling dart impact tester. Experimental results revealed retarded curing rates for all semi-IPNs, as evidenced from the shifts of curing exothermic peaks to higher temperatures, together with retarded viscosity increases during semi-IPN formation. These phenomena were interpreted in terms of chain entanglement between epoxy and PEGMEA. Nevertheless, the semi-IPNs indicated good compatibility as inferred from a single T-g in DSC and a single damping peak in RDS for each semi-IPN. Improved tensile stress and strain along with toughness improvements were noticed for this semi-IPN system. Shear band yielding was proposed to interpret this result. (C) 1999 Society of Chemical Industry.
Tooth undercutting of beveloid gears
(2001-12-01)
Liu, CC
;
Tsay, CB
;
機械工程學系
;
Department of Mechanical Engineering
A beveloid gear can be viewed as an involute gear of which the profile-shifted coefficient linearly decreases from the heel to the toe. Therefore, tooth undercutting occurs and singular points appear on the tooth surfaces near the toe. When undercutting occurs, the gear tooth is comparatively weak. In this study, the conditions of tooth undercutting of beveloid gears were derived and specific phenomena were also investigated by numerical illustrated examples. In addition, according to the characteristics of tooth undercutting on the beveloid gear tooth surface, two practicable methods were also proposed to avoid the tooth undercutting of beveloid gears.
Toughened interpenetrating polymer network materials based on unsaturated polyester and epoxy
(1999-04-25)
Lin, MS
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Liu, CC
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Lee, CT
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應用化學系
;
Department of Applied Chemistry
Simultaneous interpenetrating polymer networks (IPNs) based on epoxy (diglycidyl ether of bisphenol A) and unsaturated polyester (UP) were prepared by using m-xylenediamine and benzoyl peroxide as curing agents. A single glass transition temperature for each IPN was observed with differential scanning calorimetry, which suggests good compatibility of epoxy and UP. This compatibility was further confirmed by the single damping peak of the rheometric dynamic spectroscopy. Curing behaviors were studied with dynamic differential scanning calorimetry, and the curing rates were measured with a Brookfield RTV viscometer. It was noted that an interlock between the two growing networks did exist and led to a retarded viscosity increase. However, the hydroxyl end groups in UP catalyzed the curing reaction of epoxy; in some IPNs where the hydroxyl concentration was high enough, such catalytic effect predominated the network interlock effect, leading to fast viscosity increases. In addition, the entanglement of the two interlocked networks played an important role in cracking energy absorption and reflected in a toughness improvement. (C) 1999 John Wiley & Sons, Inc.
Two-stage Welsh's trimmed mean for the simultaneous equations model
(2001-12-01)
Chen, LA
;
Liang, KY
;
Liu, CC
;
統計學研究所
;
Institute of Statistics
This paper discusses the large sample theory of the two-stage Welsh's trimmed mean for the limited information simultaneous equations model. Besides having asymptotic normality, this trimmed mean, as the two-stage least squares estimator, is a generalized least squares estimator. It also acts as a robust Aitken estimator for the simultaneous equations model. Examples illustrate real data analysis and large sample inferences based on this trimmed mean.