Browsing by Issue Date, starting with "2005-09-01"

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Native-NMOS-triggered SCR With faster turn-on speed for effective ESD protection in a 0.13-mu m CMOS process
(2005-09-01)
Ker, MD
;
Hsu, KC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In order to quickly discharge the electrostatic discharge (ESD) energy and to efficiently protect the ultrathin gate oxide, a novel native-negative-channel metal oxide semiconductor (NMOS)-triggered silicon-controlled rectifier (NANSCR) is proposed for on-chip ESD protection in a 0.13-mu m complementary metal oxide semiconductor (CMOS) process with a voltage supply of 1.2 V. The proposed NANSCR can be designed for the input, output, and power-rail ESD protection circuits without latchup danger. A new whole-chip ESD protection scheme realized with the proposed NANSCR devices is also demonstrated with the consideration of pin-to-pin ESD stress. From the experimental results, the trigger voltage, holding voltage, turn-on resistance, turn-on speed, and charged-device-model (CDM) ESD level of NANSCR can be greatly improved, as compared with the traditional low-voltage-triggering SCR (LVTSCR). Under transmission line pulsing (TLP) stress, the gate leakage current of the gate monitor device protected by the proposed NANSCR is monitored after each TLP pulse, whereas the gate leakage current is not obviously increased. Therefore, the ultrathin gate oxide of the input stage can be safely protected by the new proposed NANSCR against ESD stress in the nanoscale CMOS technology.
本質的策略，策略的本質與解釋的策略
(國立陽明交通大學出版社, 2005-09-01)
黃錦樹
Analysis of DC characteristics and small signal equivalent circuit parameters of GaAs metal-semiconductor field effect transistors with different gate lengths and different gate contours by two-dimensional device simulations
(2005-09-01)
Meng, CC
;
Su, JY
;
Yang, SM
;
電信工程研究所
;
Institute of Communications Engineering
The gate length and gate contour of a GaAs metal-semiconductor field effect transistor (MESFET) device play important roles in determining the small signal circuit parameters and large signal breakdown voltage behavior, GaAs MESFETs with different gate lengths and gate contours were studied by the two-dimensional (2-D) semiconductor device simulations to investigate the dependence of small signal circuit parameters and breakdown voltage on gate length and gate contour. The results show that gate length affects small-signal circuit parameter C(gs) while gate contour affects C(gd). The breakdown voltage has strong dependence on gate contour and little dependence on gage length.
A new approach for audio classification and segmentation using Gabor wavelets and Fisher Linear Discriminator
(2005-09-01)
Lin, RS
;
Chen, LH
;
資訊工程學系
;
Department of Computer Science
Rapid increase in the amount of audio data demands an efficient method to automatically segment or classify audio stream based on its content. In this paper, based on the Gabor wavelet features, an audio classification and segmentation method is proposed. This method will first divide an audio stream into clips, each of which contains one-second audio information. Then, each clip is classified as one of two classes or five classes. Two classes contain speech and music; pure speech, pure music, song, speech with music background, and speech with environmental noise background are for five classes. Finally, a merge technique is provided to do segmentation. In order to make the proposed method robust for a variety of audio sources: we use Fisher Linear Discriminator to obtain features with the highest discriminative ability Experimental results show that the proposed method can achieve over 98% accuracy rate for speech and music discrimination, and more than 95% for a five-way discrimination. By checking the class types of adjacent clips, we can also identify more than 95% audio scene breaks in audio sequence.
A background comparator calibration technique for flash analog-to-digital converters
(2005-09-01)
Huang, CC
;
Wu, JT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a background calibration technique for trimming the input-referred offsets of the comparators in a flash analog-to-digital converter (ADC) without interrupting the ADC's normal operation. For a random-chopping comparator, the polarity of its offset is detected by observing the code density of its comparison results. Binary feedback is then used to digitally adjust the comparator's offset so that the offset is minimized. All calibration procedures are performed in the digital domain. The calibration performance is characterized by the converging speed of the feedback loop and the offset fluctuation due to the disturbance of the ADC's input. These two performance indexes of a background-calibrated comparator (BCC) are determined by three parameters: the probabilistic distribution of the ADC's input, the BCC's offset quantized step size, and the threshold of an internal bilateral peak detector. The offset fluctuation of a BCC can be drastically reduced by employing a windowing mechanism. The use of windowed BCCs in a flash ADC can introduce nonmonotonic-threshold (NMT) effects which include an increase in calibration settling time and an increase in sigma(V-OS). The use of uncorrelated random chopping for neighboring BCCs can ensure the validity of offset detection and mitigate the NMT effects.
ESD protection design for 1-to 10-GHz distributed amplifier in CMOS technology
(2005-09-01)
Ker, MD
;
Hsiao, YW
;
Kuo, BJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Two distributed electrostatic discharge (ESD) protection schemes are presented and applied to protect distributed amplifiers (DAs) against ESD stresses. Fabricated in a standard 0.25-mu m CMOS process, the DA with the first protection scheme of the equal-sized distributed ESD (ES-DESD) protection scheme, contributing an extra 300 fF parasitic capacitance to the circuit, can sustain the human-body model (HBM) ESD level of 5.5 kV and machine-model (MM) ESD level of 325 V and exhibits the flat-gain of 4.7 +/- l dB from 1 to 10 GHz. With the same amount of parasitic capacitance, the DA with the second protection scheme of the decreasing-sized distributed ESD (DS-DESD) protection scheme achieves better ESD robustness, where the HBM ESD level over 8 kV and MM ESD level is 575 V, and has the flat-gain of 4.9 +/- 1.1 dB over the 1 to 9.2-GHz band. With these two proposed ESD protection schemes, the broad-band RF performances and. high ESD robustness of the DA can be successfully codesigned to meet the application specifications.
Closure to "Electronic-Based procedure for managing unbalanced bids" by Wei-Chih Wang
(2005-09-01)
Wang, WC
;
土木工程學系
;
Department of Civil Engineering
Special issue on e-learning - Foreword
(2005-09-01)
Lewis, R
;
Chan, TW
;
Chou, C
;
Sun, CT
;
資訊工程學系
Analysis and design of one-bit noise-shaping quantizer using variable structure control approach
(2005-09-01)
Hu, J
;
Yu, SH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper offers a straightforward analysis of a one-bit noise-shaping quantizer based on variable structure control methods. The method uses the concept of equivalent control to access the bound on the state signals when the sliding condition is reached. For a stable loop filter, the global stability can be proved to exist by using the Lyanpunov stability theory. For an unstable loop filter, this paper proposes a state constraint approach to ensure that the sliding condition is achieved. Simulation examples and an experimental circuit constructed using off-the-shelf electronic components are given to demonstrate the correctness of the theoretical analysis.
The interplay between different forms of CAI and students' preferences of learning environment in the secondary science class
(2005-09-01)
Chang, CY
;
Tsai, CC
;
教育研究所
;
師資培育中心
;
Institute of Education
This evaluation study investigated the effects of a teacher-centered versus student-centered computer-assisted instruction (CAI) on 10th graders' earth science student learning outcomes. This study also explored whether the effects of different forms of computer-assisted instruction (CAI) on student learning outcomes were influenced by student preferences of learning environment (PLE). A total of 347 10th-grade senior high school students participated in this nonequivalent control group quasiexperiment. During a one-week period, one group of students (n = 216) were taught by a teacher-centered CAI (TCCAI) model whereas the other group of students (n = 131) were subject to a student-centered CAI (SCCAI) method. Results showed that (a) no statistically significant difference on students' earth science achievement was found for either group; (b) TCCAI, group had significantly better attitudes toward earth science than did the SCCAI group; furthermore (c) a significant PLE-treatment interaction was found on student attitudes toward the subject matter, where the teacher-centered instructional approach seemed to enhance more positive attitudes of less constructivist-oriented learning preferences students, whereas the student-centered method was more beneficial to more constructivist-oriented learning preferences students on their attitudes toward earth science in a computer-assisted learning environment. (c) 2005 Wiley Periodicals, Inc.
Influence of the direction of motion on the inelastic interaction between electrons and solid surfaces
(2005-09-01)
Li, YC
;
Tu, YH
;
Kwei, CM
;
Tung, CJ
;
電子工程學系及電子研究所
Theoretical derivations of the inelastic differential inverse mean free path (DIMFP) and inelastic mean free path (IMFP) for electrons crossing solid surfaces were made for different crossing angles and electron distances relative to the crossing point at the surface. Individual contributions from volume and surface excitations were separated and analyzed for electrons traveling inside and outside the solid. Extended Drude dielectric functions were employed to calculate the DIMFP and inverse IMFP for electrons incident into and escaping from Cu. It was found that the DIMFP and inverse IMFP for electrons moving inside the solid were approximately independent of crossing angle and position of electrons due to the compensation of volume and surface excitations. For electrons moving deep inside the solid, the DIMFP and inverse IMFP reduced to the values for electrons moving in an infinite solid. As electrons traveling in the vacuum, the DIMFP and inverse IMFP became greater for glancing incident and escaping angles since surface excitations were more probable. The surface excitation parameter (SEP) for electrons traveling in vacuum showed an angular dependence. The SEP of escaping electrons was found larger than that of incident electrons due to the attractive force exerted by the induced surface charges. The calculated SEP was found to follow a simple expression. (c) 2005 Elsevier B.V. All rights reserved.
Six-band k center dot p calculation of spin-dependent interband tunneling in strained broken-gap heterostructures under a quantizing magnetic field
(2005-09-01)
Zakharova, A
;
Nilsson, K
;
Chao, KA
;
Yen, ST
;
電子工程學系及電子研究所
We investigate spin-dependent interband magnetotunneling processes in strained broken-gap resonant tunneling structures made from InAs, AlSb, and GaSb, which are promising materials for quantum devices. InAs/AlSb/GaSb/InAs/AlSb/GaSb double-barrier structures grown on both InAs and GaSb are considered. Transmission coefficients for interband tunneling processes from individual eigenstates in the InAs emitter as well as current-voltage characteristics were calculated using a six-band k center dot p model and the scattering matrix method. We predict that due to lattice-mismatch induced strain, the interband tunneling current density for the structure grown on InAs can be one or two orders of magnitude less than that for the structure grown on GaSb. Furthermore, as a consequence of interband magnetotunneling, structures grown on different substrates yield different spin polarization of the tunneling current. It is obtained that the current spin polarization can be greater than 90%. These resonant tunneling structures can be used as spin filters in the rapidly growing field of spintronics.
Synthesis and characterization of Ni-P-CNT's nanocomposite film for MEMS applications
(2005-09-01)
Shen, GR
;
Cheng, YT
;
Tsai, LN
;
機械工程學系
;
電子工程學系及電子研究所
An electroless phosphorus nickel-carbon nanotube's (Ni-P-CNT) nanocomposite film synthesis and related process for microelectromechanical systems device fabrication have been successfully developed and presented in this paper. With a special acid oxidative method, a well-dispersed nickel-CNT's colloidal solution has been produced without any aggregation, which is very suitable for microstructure fabrication. The nanoindentation measurement indicates that the Young's modulus and hardness of the Ni-P-CNT's nanocomposite film plated in the bath with 0.028-g/L CNTs can greatly increase up to 665.9 and 28.9 GPa, respectively, which are approximately four times larger than that of pure nickel. Moreover, the content of CNTs in the Ni-P-CNT's films is measured by an elemental analyzer. Via the electrical resistivity measurement using a four-point probe, it is found that the electrical property of the nanocomposite film can be well characterized using a Maxwell-Wagner model for a two-phase mixture. The performance improvements of the electrothermal microactuator made of the nanocomposite, including device strength and power efficiency, have been proven similar to the actuator made of the Ni-diamond composites by electrolytic plating by Tsai et al, but with more efficiency and higher strength than the Ni-diamond device does.
Assessment of fire protection performance of water mist applied in exhaust ducts for semiconductor fabrication process
(2005-09-01)
Shu, YL
;
Jeng, WJ
;
Chiu, CW
;
Chen, CH
;
機械工程學系
Fume exhaust pipes used in semiconductor facilities underwent a series of fire tests to evaluate the performance of a water mist system. The parameters considered were the amount of water that the mist nozzles used, the air flow velocity, the fire intensity and the water mist system operating pressure. In order to make a performance comparison, tests were also performed with a standard sprinkler system. The base case served as a reference and applied a single water mist nozzle (100 bar operating pressure, 7.31/min water volume flux and 200 pin mean droplet size) installed in the pipe (60 cm in diameter) subjected to a 350 degrees C air flow with an average velocity of 2 m/s. In such a case, the temperature in the hot flow dropped sharply as the water mist nozzle was activated and reached a 60 degrees C saturation point. Under the same operating conditions, four mist nozzles were applied, and made no further contribution to reducing the fire temperature compared with the case using only a single nozzle. Similar fire protection performances to that in the base case were still retained when the exhaust flow velocity increased to 3 m/s and the inlet air temperature was increased to 500 degrees C due to a stronger input fire scenario, respectively. Changing to a water mist system produced a better performance than a standard sprinkler. With regard to the effect of operating pressure of water mist system, a higher operating pressure can have a better. performance. The results above indicate that the droplet size in a water-related fire protection system plays a critical role. Copyright (c) 2005 John Wiley & Sons, Ltd.
The design and implementation of a diagnostic test system based on the enhanced S-P model
(2005-09-01)
Chen, DJ
;
Lai, AF
;
Liu, IC
;
資訊工程學系
;
Department of Computer Science
The cognitive diagnostic test can be used to understand the learning effects (such as strengths and weaknesses) of learners for a specific subject area. Based on the evaluation results of the diagnostic test, instructors may suggest or give students additional material on the subject area for students who do not meet the requirements. The S-P (Student-Problem) model has been used for this purpose for a long time. However, the current S-P model pays little attention to a student's response time for each test item or for the entire question set during the test. The student's response time for each test item can be an important factor for instructors wanting to diagnose each student's individual ability in problem solving. Also, there are few computerized diagnostic test analysis systems available that are designed to support both text-diagram-based and/or multimedia-based presentation test items. In this research, we incorporate the response time, difficulty index, and discriminatory index of each test item into an S-P model during the analysis. Specifically, we employ two terms: 1) the nimbleness of thinking of a student, which can be measured based on the response time for answering each test item, and 2) the problem solving ability of a student, which can be measured based on the student's ability to solve adaptive type questions with various difficulty levels and discrimination powers. With the incorporation of these parameters, an enhanced S-P model is presented. It can be used to diagnose both time dependent information and problem solving abilities with respect to test items and test-takers. A web-based computerized system was designed and implemented based on the enhanced S-P model for both text-diagram type presentation test items and multimedia type presentation test items. Practical examples were investigated and experimental studies conducted using the cognitive diagnostic computerized system to demonstrate the rationality and applicability of the proposed enhanced S-P model.
Impact of thermal effects on simulation accuracy of nonlinear dynamics in semiconductor lasers
(2005-09-01)
Lim, CG
;
Iezekiel, S
;
Snowden, CM
;
光電工程學系
;
Department of Photonics
Simulations based on a carrier heating model are performed to investigate the behavior of a directly modulated 1.55-mu m InGaAsP distributed feedback (DFB) laser diode (LD). Results show that bandgap shrinkage has a significant effect on the simulated nonlinear behavior of LDs. However, the varying nature of lattice temperature and excess carrier energy relaxation is important to produce simulated results that agree with measured results.
利用法布里-珀羅（Fabry-Perot）雷射二極體之快速波長可調雷射系統
(2005-09-01)
祁甡
;
李健仲
;
葉建宏
本發明揭示一種以多模波長輸出的法布里–珀羅(Fabry–Perot)雷射二極體作為外部注入光源及共振腔來達成快速波長可調之雷射系統，其中波長可調之功能可藉由改變控制外注入式多模法布里–珀羅(Fabry–Perot)雷射二極體最大光增益的偏壓而取得波長的反覆切換，藉此系統，可在3.5奈米(nm)波長範圍內選取3個不同的波長，且其旁模壓抑比(Side–Mode Suppression Ratio)可大於19dB，其波長切換時間亦可達到奈秒(ns)的等級。
對吳叡人、黃錦樹兩位教授意見的回應
(國立陽明交通大學出版社, 2005-09-01)
蕭阿勤
Study of diffusion and quality control for CoSi2 formation by oxide-mediated cobalt silicidation with Ti capping
(2005-09-01)
Chang, JJ
;
Liu, CP
;
Hsieh, TE
;
Wang, YL
;
材料科學與工程學系
The mechanism for the enhancement Of COSi2 thin film formation and film quality control by oxide-mediated cobalt silicidation with a Ti-capping layer is discussed. It is found that Ti absorbs oxygen from the SiOx layer, which induces weak points in the SiOx layer and then enhances Co diffusion as well as COSi2 formation. The control of the reactions between Ti and SiOx is significant because a low reaction rate cannot form a suitable thickness Of CoSi2 film, whereas a high reaction rate tends to form the highly resistive CoSi phase. In addition, to maintain the SiOx layer still existing after annealing is also important because if no SiOx layer remains, unreacted Co would react with Si directly to form the highly resistive phase of CoSi, leading to the smooth interface between CoSi2 and Si and dense bulk CoSi2 thin film being destroyed. (c) 2005 American Vacuum Society.
Effect of substrate orientation on arsenic precipitation in low-temperature-grown GaAs
(2005-09-01)
Lee, WN
;
Chen, YF
;
Huang, JH
;
Guo, XJ
;
Kuo, CT
Arsenic precipitation in "superlattice" structures of alternately undoped and [Si] = 3 x 10(18) cm(-3)-doped GaAs grown at 250 degrees C on (100), (311)A, and (311)B GaAs substrates has been studied using transmission electron microscopy. It is found that upon postgrowth annealing at 800 degrees C, As precipitates are nearly confined in the Si-doped regions, forming two-dimensional cluster arrays located approximately at the center of each Si-doped layer. The results also show that the As precipitates in the (311)B substrate are slightly denser and larger than those in the (311)A substrate and both are markedly denser and larger than those in the (100) substrate. This can be attributed to the varying excess arsenic incorporations in differently orientated substrates.