Browsing by Author "Chen, Yi-Hsuan"

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4 Tunability and Optimization of Coupling Efficiency in Tamm Plasmon Modes
(2015-07-01)
Chang, Che-Yuan
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Chen, Yi-Hsuan
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Tsai, Yu-Lin
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Kuo, Hao-Chung
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Chen, Kuo-Ping
A Tamm plasmon polariton is a plasmonic resonance excited at the boundary between a photonic crystal and a metal. In this paper, a novel approach based on admittance loci is proposed to demonstrate the relation between thin-film structures and the corresponding Tamm plasmon modes. The tunability of the resonance wavelength and optimization of coupling efficiency are demonstrated. In addition, by using different metals to couple Tamm plasmon modes in the visible spectrum, silver has 4.7 times larger Q-factor than gold and 84 times larger than aluminum at 700 nm. The near-field enhancement of silver Tamm plasmon modes could be up to eight times larger than incident EM waves.
A fuzzy MCDM approach for evaluating banking performance based on Balanced Scorecard
(2009-08-01)
Wu, Hung-Yi
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Tzeng, Gwo-Hshiung
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Chen, Yi-Hsuan
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科技管理研究所
;
Institute of Management of Technology
The paper proposed a Fuzzy Multiple Criteria Decision Making (FMCDM) approach for banking performance evaluation. Drawing on the four perspectives of a Balanced Scorecard (BSC), this research first summarized the evaluation indexes synthesized from the literature relating to banking performance. Then, for screening these indexes, 23 indexes fit for banking performance evaluation were selected through expert questionnaires. Furthermore, the relative weights of the chosen evaluation indexes were Calculated by Fuzzy Analytic Hierarchy Process (FAHP). And the three MCDM analytical tools of SAW, TOPSIS, and VIKOR were respectively adopted to rank the banking performance and improve the gaps with three banks as an empirical example. The analysis results highlight the critical aspects of evaluation criteria as well as the gaps to improve banking performance for achieving aspired/desired level. It shows that the proposed FMCDM evaluation model of banking performance using the BSC framework can be a useful and effective assessment tool. (C) 2009 Elsevier Ltd. All rights reserved.
An Experimental Study of DLV Method in Damage Detection of Frame Structures
(2010)
Wang, Yen-Po
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Chen, Yi-Hsuan
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Lee, Chien-Liang
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土木工程學系
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Department of Civil Engineering
A structural damage detection method integrating the damage locating vector (DLV) method and ARX model for system identification of frame structures from seismic acceleration responses has been explored in this paper. The concept of the DLV method is to identify the members with zero stress under some specific loading patterns derived from the changes in flexibility matrix of the structure before and after the damage state. Success of the DLV method requires clear identification of the flexibility matrix for at least the first few dominant modes. In this study, a five-storey steel frame with diagonal bracings is considered as the objective building. The damage condition of the structure is simulated by partially removing some of the diagonals. With the flexibility matrices of both the intact and damaged structure identified from seismic structural responses via shaking table tests, results indicate that the damaged locations can be successfully identified by the DLV method if sufficient modes of vibration are taken into account in the realization of the flexibility matrices. The feasibility of using DLV method for damage detection of frame structures using seismic response data is confirmed.
Default correlation at the sovereign level: evidence from some Latin American markets
(2011)
Chen, Yi-Hsuan
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Wang, Kehluh
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Tu, Anthony H.
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
Using the eruption of Argentina debt crisis in 2001 as a natural experiment, we investigated the correlated default at the sovereign level for some Latin American countries. Daily closing market quotes for sovereign Credit Default Swaps (CDS) of Argentina, Brazil, Mexico and Venezuela were obtained from CreditTrade database. Using copula approach, we observed increased dependences among sovereign CDS markets during the crisis period. Their dependence structures were found to be asymmetric. Moreover, the degree of credit contagion was related to the creditworthiness of the country. This study also discussed the implications of these findings for policymakers.
Design tables and charts for uniform and non-uniform tuned liquid column dampers in harmonic pitching motion
(2012-02-01)
Wu, Jong-Cheng
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Wang, Yen-Po
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Chen, Yi-Hsuan
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土木工程學系
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Department of Civil Engineering
In the first part of the paper, the optimal design parameters for tuned liquid column dampers (TLCD) in harmonic pitching motion were investigated. The configurations in design tables include uniform and non-uniform TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 for the design in different situations. A closed-form solution of the structural response was used for performing numerical optimization. The results from optimization indicate that the optimal structural response always occurs when the two resonant peaks along the frequency axis are equal. The optimal frequency tuning ratio, optimal head loss coefficient, the corresponding response and other useful quantities are constructed in design tables as a guideline for practitioners. As the value of the head loss coefficient is only available through experiments, in the second part of the paper, the prediction of head loss coefficients in the form of a design chart are proposed based on a series of large scale tests in pitching base motions, aiming to ease the predicament of lacking the information of head loss for those who wishes to make designs without going through experimentation. A large extent of TLCDs with cross-sectional ratios of 0.3, 0.6, 1, 2 and 3 and orifice blocking ratios ranging from 0%, 20%, 40%, 60% to 80% were inspected by means of a closed-form solution under harmonic base motion for identification. For the convenience of practical use, the corresponding empirical formulas for predicting head loss coefficients of TLCDs in relation to the cross-sectional ratio and the orifice blocking ratio were also proposed. For supplemental information to horizontal base motion, the relation of head loss values versus blocking ratios and the corresponding empirical formulas were also presented in the end.
Development of physical-parameter identification procedure for in-situ buildings with sliding-type isolation system
(2013-06-24)
Huang, Ming-Chih
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Wang, Yen-Po
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Lin, Tzu-Kang
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Chen, Yi-Hsuan
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土木工程學系
A system identification procedure is developed to identify the physical parameters of structures with seismic isolation using the friction pendulum systems (FPSs). The superstructure is assumed to be linear on account of substantial reduction of seismic forces with the installation of FPS. Hysteretic models of both Coulomb's and Mokha's friction mechanism have been considered for the FPS. Simulation results indicate that the physical parameters of the FPS and superstructure can be successfully identified by the proposed scheme. Experimental verification has been conducted further via shaking table tests using realistic earthquake scenarios. The identified parameters from seismic response data indicate that the FPSs behave in better agreement with Mokha's friction mechanism than Coulomb's. Feasibility of the proposed scheme in the identification of FPS-isolated structures using seismic data has been verified. This may facilitate in-situ performance assessment of structures isolated with sliding-type isolation systems. (C) 2013 Elsevier Ltd. All rights reserved.
Effects of Annealing on Ferroelectric Hafnium-Zirconium-Oxide-Based Transistor Technology
(2019-03-01)
Chen, Yi-Hsuan
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Su, Chun-Jung
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Hu, Chenming
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Wu, Tian-Li
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國際半導體學院
In this letter, we investigate annealing effects in ferroelectric HfZrOx dielectric in metal-insulator-metal devices and metal-oxide-semiconductor capacitors by comparing two annealing methods: rapid thermal annealing (RTA) and microwave annealing (MWA). The tradeoff characteristics between the annealing conditions, polarization-electric field characteristics, gate leakage current, and interface state density (D-it) are discussed. We show that: 1) a positive correlation between the remanent polarization (Pr), the gate leakage current, and D-it as the annealing temperature (RTA) and the annealing power (MWA) increase and 2) the MWA is promising for ferroelectric transistors technology, since its low thermal budget can minimize D-it and avoid increase in the gate leakage current.
High-performance poly-Si TFT with ultra-thin channel film and gate oxide for low-power application
(2015-10-01)
Chen, Yi-Hsuan
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Ma, William Cheng-Yu
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Chao, Tien-Sheng
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電子物理學系
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Department of Electrophysics
In this paper, an ultra-thin-body thin-film transistor (UTB-TFT) with a raised source/drain structure is demonstrated and compared with a conventional thin-film transistor. A significant suppression of leakage current and an improvement in subthreshold swing (SS) resulting from the reduced body thickness is observed. The minimum current can be decreased from 245 pA to 42 pA as the channel film thickness is scaled down from 60 nm to 10 nm. However, an ultra-thin-channel film constrains the average grain size and severely impacts the saturation current. Fortunately, by decreasing the gate oxide thickness from 20 nm to 10 nm, the saturation current of a UTB-TFT can be significantly increased from 13 mu A to 25 mu A. Experimental results suggest that UTB-TFTs with a sub-10 nm gate oxide display great promise for future low-power, high-performance three-dimensional integrated circuits.
High-Performance Poly-Si Thin-Film Transistors With L-Fin Channels
(2012-02-01)
Lu, Yi-Hsien
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Kuo, Po-Yi
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Lin, Je-Wei
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Wu, Yi-Hong
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Chen, Yi-Hsuan
For the first time, we construct poly-Si thin-film transistors (TFTs) with novel L-shaped poly-Si fin channels (poly-Si TFTs with L-fin channels, called LFin-TFTs). The L-fin channels of LFin-TFTs are similar to the multiple-gated fin channels of FinFETs. The LFin-TFTs exhibit a low supply gate voltage (3 V), a good subthreshold swing (SS) similar to 190 mV/dec, and a high on/off current ratio (I-ON/I-OFF) > 10(6) (V-D = 1 V) without hydrogen-related plasma treatments. After Ni salicidation, the devices exhibit steep SS similar to 148 mV/dec and I-ON/I-OFF similar to 10(7). After NH3 plasma treatment, the characteristics of the devices are further improved. The LFin-TFTs have steeper SS similar to 132 mV/dec, higher I-ON/I-OFF > 10(7), and threshold voltage (V-TH) similar to 0.036 V.
High-performance sidewall damascened tri-gate poly-si TFTs with the strain proximity free technique and stress memorization technique
(2017-02)
Hsieh, Dong-Ru
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Kuo, Po-Yi
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Lin, Jer-Yi
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Chen, Yi-Hsuan
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Chang, Tien-Shun
In this paper, strained channel-sidewall damascened tri-gate polycrystalline silicon thin-film transistors (SC-SWDTG TFTs) have been successfully fabricated and then demonstrated by an innovative process flow. This process flow without the use of advanced lithography processes combines the sidewall damascened technique (SWDT) and two strain techniques, namely, the strain proximity free technique (SPFT), and the stress memorization technique (SMT), in the poly-Si channels. It has some advantages: (1) the channel shapes and dimensions can be effectively controlled by the wet etching processes and the deposition thickness of the tetraethoxysilane (TEOS) oxide; (2) the source/drain (S/D) resistance can be significantly decreased by the formation of the raised S/D structures; (3) the SPFT, SMT, and the rapid thermal annealing (RTA) treatment can enhance the performance of the SC-SWDTG TFTs without the limitation of the highly scaling stress liner thickness in deep-submicron TFTs. Thus, the SC-SWDTG TFTs exhibit a steep subthreshold swing (S.S.) similar to 110mV/dec., an extremely small drain induced barrier lowing (DIBL) similar to 12.2mVV(-1), and a high on/off ratio similar to 10(7) (V-D = 1V) without plasma treatments for future three-dimensional integrated circuits (3D ICs) applications.
Impact of Crystallization Method on Poly-Si Tunnel FETs
(2015-10-01)
Chen, Yi-Hsuan
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Ma, William Cheng-Yu
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Lin, Jer-Yi
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Lin, Chun-Yen
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Hsu, Po-Yang
In this letter, the impact of crystallization method on the electrical characteristics of polycrystalline silicon (poly-Si) tunnel field-effect transistors (TFETs) is investigated. Different crystallization methods may result in different amounts of interface traps (N-it) and bulk traps (N-GB). TFETs crystallized with solid-phase crystallization (SPC) and metal-induced lateral crystallization (MILC) were fabricated and compared. In comparison with the SPC TFETs, the MILC TFETs exhibit similar to 4.5x higher ON-state current I-ON, subthreshold swing reduction Delta S.S. similar to 202 mV/decade, and larger similar to 7.2x ON/OFF current ratio. According to the measurement of a monitor poly-Si thin-film transistor, replacing SPC with MILC results in a reduced N-it similar to 0.60x and a reduced N-GB similar to 0.36x, respectively. It can enhance the gate-to-tunnel junction controllability. Consequently, lowering trap density favors reducing power consumption of TFETs and provides a promising solution for future low-power driving circuits in portable electronics.
Improved TDDB Reliability and Interface States in 5-nm Hf0.5Zr0.5O2 Ferroelectric Technologies Using NH3 Plasma and Microwave Annealing
(2020-04-01)
Chen, Yi-Hsuan
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Su, Chun-Jung
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Yang, Ting-Hsin
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Hu, Chenming
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Wu, Tian-Li
This article reports that the enhanced forward gate bias time-dependent dielectric breakdown (TDDB) reliability and interface quality are achieved in 5-nm ferroelectric Hf0.5Zr0.5O2 (HZO) technologies by using the NH3 plasma interfacial layer (IL) treatment and microwave annealing (MWA). An orthorhombic crystalline phase is observed in the annealed HZO film with NH3 plasma IL treatment and MWA, and NH3 plasma IL treatment can suppress Hf/Zr interdiffusion. Metal-oxide-semiconductor capacitors (MOSCAPs) subjected to NH3 plasma IL treatment and 2100-W MWA also have a higher extrapolated operating voltage for a ten-year lifetime at 0.01% failure and lower interface state density compared to the devices subjected to only rapid thermal annealing (RTA) at 600 degrees C. Therefore, NH3 plasma treatment and MWA are effective for improving the TDDB reliability and interface quality of the ultrathin ferroelectric HZO.
Low-Temperature Polycrystalline-Silicon Tunneling Thin-Film Transistors With MILC
(2013-08-01)
Chen, Yi-Hsuan
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Yen, Li-Chen
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Chang, Tien-Shun
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Chiang, Tsung-Yu
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Kuo, Po-Yi
It is known that metal-induced lateral crystallization (MILC) thin-film transistors (TFTs) exhibit higher on-state current, steeper subthreshold slope, and lower minimum leakage than solid-phase-crystallization TFTs. In this letter, we propose a tunneling TFT (T-TFT) fabricated by MILC method for the first time. The MILC T-TFTs demonstrate a lower subthreshold swing, similar to 232 mV/decade, than the other T-TFTs and a high ON/OFF ratio > 10(6) at V-DS = 1 V without any hydrogen-related plasma treatment. These improvements can be due to the reduction of defects at grain boundaries and the channel direction parallel to grains. The polycrystalline silicon T-TFTs fabricated in this letter show a great promise for low standby power circuits, drivers of active-matrix liquid crystal displays, and 3-D integrated circuits applications in the future.
miRNAMap 2.0: genomic maps of microRNAs in metazoan genomes
(2008-01-01)
Hsu, Sheng-Da
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Chu, Chia-Huei
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Tsou, Ann-Ping
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Chen, Shu-Jen
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Chen, Hua-Chien
MicroRNAs (miRNAs) are small non-coding RNA molecules that can negatively regulate gene expression and thus control numerous cellular mechanisms. This work develops a resource, miRNAMap 2.0, for collecting experimentally verified microRNAs and experimentally verified miRNA target genes in human, mouse, rat and other metazoan genomes. Three computational tools, miRanda, RNAhybrid and TargetScan, were employed to identify miRNA targets in 3-UTR of genes as well as the known miRNA targets. Various criteria for filtering the putative miRNA targets are applied to reduce the false positive prediction rate of miRNA target sites. Additionally, miRNA expression profiles can provide valuable clues on the characteristics of miRNAs, including tissue specificity and differential expression in cancer/normal cell. Therefore, quantitative polymerase chain reaction experiments were performed to monitor the expression profiles of 224 human miRNAs in 18 major normal tissues in human. The negative correlation between the miRNA expression profile and the expression profiles of its target genes typically helps to elucidate the regulatory functions of the miRNA. The interface is also redesigned and enhanced. The miRNAMap 2.0 is now available at http://miRNAMap.mbc.nctu.edu.tw/.
Modelling and optimisation of a two-server queue with multiple vacations and working breakdowns
(1970-01-01)
Yang, Dong-Yuh
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Chen, Yi-Hsuan
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Wu, Chia-Huang
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工業工程與管理學系
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Department of Industrial Engineering and Management
This paper presents a steady-state analysis of an M/M/2 queue with heterogeneous servers (Server 1 and Server 2). Server 1 is reliable and may leave for a vacation when the system becomes empty. Sever 2 is unreliable and may break down while serving customers. When a breakdown occurs, Server 2 reduces the service rate rather than halting service. We formulate this queueing model as a quasi birth-and-death (QBD) process, using the matrix geometric method to compute the stationary distribution of system size. We also develop several measures to evaluate the performance of the system. A cost model based on system performance measures is formulated as a heuristic cost optimisation problem subject to stability conditions. A canonical particle swarm optimisation algorithm is used to obtain numerical solutions for the approximate optimal service rates of Server 1 and Server 2. Moreover, we present numerical results showing the effects of various parameters on the approximate optimal service rates as well as a practical example illustrating the application of the proposed model.
Mutual Fund Performance Evaluation System Using Fast Adaptive Neural Network Classifier
(2008)
Wang, Kehluh
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Huang, Szuwei
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Chen, Yi-Hsuan
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交大名義發表
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National Chiao Tung University
Application of financial information systems requires instant and fast response for continually changing market conditions. The purpose of this paper is to construct a mutual fund performance evaluation model utilizing the fast adaptive neural network classifier (FANNC), and to compare our results with those from a backpropagation neural networks (BPN) model. In our experiment, the FANNC approach requires much less time than the BPN approach to evaluate mutual fund performance. RMS is also superior for FANNC. These results hold for both classification problems and for prediction problems, making FANNC ideal for financial applications which require massive volumes of data and routine updates.
Novel Sub-10-nm Gate-All-Around Si Nanowire Channel Poly-Si TFTs With Raised Source/Drain
(2011-02-01)
Lu, Yi-Hsien
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Kuo, Po-Yi
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Wu, Yi-Hong
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Chen, Yi-Hsuan
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Chao, Tien-Sheng
We have successfully fabricated novel sub-10-nm gate-all-around Si nanowire (NW) poly-Si TFTs with raised source/drain structure (GAA RSDNW-TFTs). The Si NW dimension is about 7 x 12 nm. A superior smooth elliptical shape is obtained, for the first time, in the category of poly-Si NW TFTs through the use of a novel fabrication process requiring no advanced lithographic tools. The GAA RSDNW-TFTs exhibit low supply gate voltage (3 V), steep subthreshold swing similar to 99 mV/dec, and high I(ON)/I(OFF) > 10(7) (V(D) = 1 V) without hydrogen-related plasma treatments. Furthermore, the DIBL of GAA RSDNW-TFTs is well controlled. These improvements can be attributed to the 3-D gate controllability, raised S/D structure, and sub-10-nm Si NW channel. These novel GAA RSDNW-TFTs are, thus, quite suitable for system-on-panel and 3-D IC applications.
Novel Symmetric Vertical-Channel Ni-Salicided Poly-Si Thin-Film Transistors With High ON/OFF-Current Ratio
(2010-11-01)
Wu, Yi-Hong
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Kuo, Po-Yi
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Lu, Yi-Hsien
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Chen, Yi-Hsuan
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Chao, Tien-Sheng
We have successfully fabricated the symmetric vertical-channel Ni-salicided polycrystalline silicon thin-film transistors (VSA-TFTs) for the first time. The transfer characteristics of VSA-TFTs show a sharp turning between subthreshold and ON state. The OFF-state currents can be improved by a modified overetching of oxide, equivalent dual-gate structure, and n(+) floating-region length. The ON-state currents can be enhanced by Ni-salicidation. The VSA-TFTs display a good subthreshold swing of 220 mV/dec, steep mobility increase (field-effect mobility of 76 cm(2)/ V . s), and large ON/OFF-current ratio of more than 109 (I(OFF) = 4 x 10 (14), I(ON) = 7 x 10 (5), and W(mask)/L(mask) = 10 mu m/3 mu m).
Performance Improvement of Poly-Si Tunnel FETs by Trap Density Reduction
(2016-02-01)
Cheng-Yu, William
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Chen, Yi-Hsuan
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電子物理學系
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Department of Electrophysics
In this brief, the tunnel FETs (TFETs) with a polycrystalline-Si (poly-Si) channel have been demonstrated, and the performance of the poly-Si TFET shows a significant improvement by the reduction of interface trap states (N-it) near the conduction band edge. The ON-state current (I-ON) conduction mechanism, band-to-band tunneling, of poly-Si TFETs is strongly affected by the band bending of poly-Si channel. The N-2 plasma surface treatment before the gate dielectric deposition can produce a plasma-induced interfacial layer to reduce N-it obviously, which greatly enhances the surface potential modulation by the gate and improves the I-ON value of poly-Si TFETs similar to 3.7x. The OFF-state current (I-min) attributed to the trap-assisted tunneling (TAT) can also be reduced by a factor of similar to 40%, because of the passivation of grain boundary trap (N-trap) of the poly-Si channel film. Consequently, the ON/OFF current ratio is enhanced from 9.42 x 10(5) to 6.13 x 10(6). In addition, the subthreshold swing, I-ON, and I-min of poly-Si TFET exhibit superior short-channel effect immunity, which shows good feasibility for implementing high packing density of poly-Si thin-film transistors, such as 3-D nonvolatile memory and pixel driving device.
Performance improvement of poly-Si tunnel thin-film transistor by NH3 plasma treatment
(2016-11-01)
Ma, William Cheng-Yu
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Chen, Yi-Hsuan
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Lin, Zheng-Yi
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Huang, Yao-Sheng
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Huang, Bo-Siang
In this paper, low-temperature polycrystalline silicon (poly-Si) tunnel thin-film transistors (tunnel-TFTs) are demonstrated to show excellent short-channel effects immunity due to their special current transport mechanism: inter-band tunneling. The ammonia (NH3) plasma surface treatment before the deposition of gate dielectric can significantly reduce the grain boundary trap state densities (N-GB) of poly-Si channel film and the interface trap state densities (N-it) at the gate-oxide/poly-Si interface. About 27% reduction of N-GB by NH3 plasma surface treatment can reduce the minimum drain current similar to 0.51x and improve the subthreshold slope due to the suppression of trap-assisted tunneling, which dominates the current transport in the subthreshold operation region. In addition, about 37% reduction of N-it by NH3 plasma surface treatment can significantly enhance the on-state current similar to 2.86x due to the increase of band bending of poly-Si channel potential, which can decrease the tunneling distance to increase the electron tunneling probability. Consequently, the performance improvement of poly Si tunnel-TFTs by the NH3 plasma surface treatment would be helpful for the development of system-on-panel and three-dimension integrated circuits. (C) 2016 Elsevier B.V. All rights reserved.