Browsing by Author "Chen, HL"

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A new I-V model considering the impact-ionization effect initiated by the DIGBL current for the intrinsic n-channel poly-Si TFT's
(1999-04-01)
Chen, HL
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Considering the impact-ionization mechanism occurring in the high drain-bias (V-DS) regime, a new I-V model considering the impact-ionization effect initiated by the drain-induced-grain-barrier-lowering (DIGBL) current has been established for the intrinsic n-channel poly-Si TFT, The simulation results with considering the developed impact-ionization current model are in excellent agreement with the experimental output characteristics of the intrinsic n-channel poly-Si TFT with the mask-gate length ranging from 5 mu m to 40 mu m. In resolving the physical parameters and their underlying operation mechanisms including the grain-barrier height, DIGBL current, and impact-ionization current, the developed I-V model will be beneficial to further understand the underlying physics of the intrinsic poky-Si TFT.
An analytical grain-barrier height model and its characterization for intrinsic poly-Si thin-film transistor
(1998-10-01)
Chen, HL
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An analytical model for the grain-barrier height of the intrinsic poly-Si thin-film transistors (TFT's) is developed, in which the grain-barrier height for the applied gate voltage smaller than the threshold voltage is obtained by solving the charge neutrality equation and the grain-barrier height for the applied gate voltage larger than the threshold voltage is obtained by using the quasi-two-dimensional (2-D) method. Good agreements between experimental and simulation results are obtained for wide gate voltage range.
An analytical grain-barrier height model and its characterization for intrinsic poly-Si thin-film transistor
(1998-10-01)
Chen, HL
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An analytical model for the grain-barrier height of the intrinsic poly-Si thin-film transistors (TFT's) is developed, in which the grain-barrier height for the applied gate voltage smaller than the threshold voltage is obtained by solving the charge neutrality equation and the grain-barrier height for the applied gate voltage larger than the threshold voltage is obtained by using the quasi-two-dimensional (2-D) method. Good agreements between experimental and simulation results are obtained for wide gate voltage range.
Arbitrary convex and concave rectilinear module packing using TCG
(2002)
Lin, JM
;
Chen, HL
;
Chang, YW
;
資訊工程學系
;
Department of Computer Science
In this paper, we deal with arbitrary convex and concave rectilinear module packing using the Transitive Closure Graph (TCG) representation. The geometric meanings of modules are transparent to TCG and its induced operations, which makes TCG an ideal representation for floor-planning/placement with arbitrary rectilinear modules. We first partition a rectilinear module into a set of submodules and then derive necessary and sufficient conditions of feasible TCG for the submodules. Unlike most previous works that process each submodule individually and thus need post processing to fix deformed rectilinear modules, our algorithm treats a set of submodules as a whole and thus not only can guarantee the feasibility of each perturbed solution but also can eliminate the need of the post processing on deformed modules, implying better solution quality and running time. Experimental results show that our TCG-based algorithm is capable of handling very complex instances; further, it is very efficient and results in better area utilization than previous work.
Fabrication of sub-60-nm contact holes in silicon dioxide layers
(2004-06-01)
Ko, FH
;
You, HC
;
Chu, TC
;
Lei, TF
;
Hsu, CC
We have developed a fabrication technique, comprising electron-beam writing, chemical shrinking, and silicon dioxide etching, for the fabrication of sub-60-nm contact holes. The dimensions of the contact holes after the electron-beam writing, chemical shrinkage, and plasma etching steps were 140, 93, and 53 nm, respectively. We carefully evaluated the critical process parameters, such as mixing-bake temperature, mixing-bake time, plasma etch selectivity, and the profile shapes. A higher mixing-bake temperature led to an overhang of the contact hole in the resist; the optimal mixing-bake conditions occur when heating at 110 degreesC for 70 s. A fluorinated mixture of gases (CHF3/CF4 = 1:1) was used to etch the nano-scale contact holes in the silicon dioxide layer. The formation of side-wall polymers during the plasma etch phase contributed further to the contact hole shrinkage in addition to resist chemical shrinkage. The ratio of the hole's perimeter to its area affects the shrinkage dimensions of the etch process, especially for smaller contact holes. The pattern reduction due to side-wall polymer deposition in etch process has the inverse relationship with the diameter of contact hole. (C) 2004 Elsevier B.V. All rights reserved.
Mechanism and modeling of ring pattern formation for electron beam exposure on Zwitterresist
(2003-06-01)
Chen, JK
;
Ko, FH
;
Chen, HL
;
Chang, FC
;
應用化學系
The novel sensitivity curve was determined for the zwitterresist. The irradiation dose in the center could create a ring pattern due to simultaneous exhibition of the positive tone and negative tone of zwitterresist. The natural logarithm dependence of ring width and electron beam dose was linear in two ranges, irrespective of the dot design radius. The heating effect was identified from 600 muC/cm(2), while it could be neglected at less than 600 muC/cm(2). Mathematical modeling for the prediction of ring width for zwitterresist, was achieved by considering the electron scattering and heating effects. The results of experimental measurement and modeling on ring width showed a very good correlation.
Preparation of anisotropic films for liquid crystal display application
(1998)
Hsu, CS
;
Chen, HL
;
應用化學系
;
Department of Applied Chemistry
The photoinitated polymerization of 2-chloro-1, 4-phenylene bis[4-[6-(acryloyloxy)hexyloxy]benzoate](1M) and trans-1, 4-bis(4-(2-(2,3-epoxypropyloxy)-ethoxy)-phenyl)-cyclohexyldicarboxylate (3M) were studied. Both monomers exhibit a wide temperature range of nematic phase. The monomers were oriented in their nematic phase at a substrate having been coated with polyimide and unidirestionally rubbed with a nylon cloth. During polymerization, the ordering of the LC molecules was fixed, yielding a uniaxially crosslinked network. The clear LC networks exhibit a birefringence between 0.14 and 0.19, depending on the polymerization temperature. Finally, the nonmesogenic diluents. tetra(ethylene glycol) diacryalte and 1,2-bis(2,3-expoxypropyloxy)ethane were mixed with monomers 1M and 3M, subsequently decreasing the birefringences of the obtained LC networks. The LC networks containing non-mesogenic diluent exhibit not only a smaller birefringence but also a weaker birefringence dispersion in the visible region.
Preparation of liquid-crystal thermosets: In situ photopolymerization of oriented liquid-crystal diacrylates
(1999-11-01)
Hsu, CS
;
Chen, HL
;
應用化學系
;
Department of Applied Chemistry
The photoinitiated polymerization of 2-chloro-1,4-phenylene bis[4-[6-(acryloyloxy)hexyloxy]benzoate] (1M) was studied. The monomer 1M exhibited a broad nematic phase between 24.9 and 113.7 degrees C on a DSC cooling scan. It was oriented in its nematic phase at a substrate coated with polyimide and unidirectionally rubbed with a nylon cloth. During polymerization, the ordering of the liquid-crystal molecules was fixed, yielding a uniaxially crosslinked network. The clear liquid-crystal networks (LCNs) exhibited a birefringence between 0.14 and 0.19, depending on the polymerization temperature. Finally, a nonmesogenic diluent, tetra(ethylene glycol)diacrylate, was mixed with 1M, subsequently decreasing the birefringence of the obtained LCNs. The LCNs containing nonmesogenic diluent exhibited not only a smaller birefringence but also a weaker birefringence dispersion in the visible region. (C) 1999 John Wiley & Sons, Inc.
Synthesis of anisotropic polymer films for display applications
(1997-04-13)
Hsu, CS
;
Chen, HL
;
應用化學系
;
Department of Applied Chemistry
Voltage controlled liquid crystal terahertz quarter wave plate
(2005)
Hsieh, CF
;
Chen, HL
;
Chen, CY
;
Pan, RP
;
Pan, CL
We demonstrate an electrically switchable THz quarter wave plate using nematic liquid crystals.
Voltage-controlled liquid-crystal terahertz phase shifter and quarter-wave plate
(2006-04-15)
Hsieh, CF
;
Pan, RP
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Tang, TT
;
Chen, HL
;
Pan, CL
Phase shift exceeding pi/2 at 1 THz is demonstrated by using electrically controlled birefringence in a homeotropically aligned nematic liquid crystal (E7) cell, 570 mu m in thickness. The driving voltage required for a phase shift of 90 degrees is 125 V (rms). We demonstrate that the phase shifter works as an electrically switchable quarter-wave plate at I THz. The device can also be used as an electrically tuned phase compensator around the quarter-wave point near 1 THz. (c) 2006 Optical Society of America.