Browsing by Author "Wu, CH"

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A more expressive monitor for concurrent Java programming
(2000)
Chiao, HT
;
Wu, CH
;
Yuan, SM
;
資訊工程學系
;
Department of Computer Science
The thread synchronization mechanism employed by Java is derived from the Hoare's monitor concept. In order to minimize its implementation complexity, the monitor provided by Java is quite primitive. This design decision prefers simple concurrent objects and single-thread programs. However, we think the Java monitor is over simplified for developing more elaborated concurrent objects. Besides, several features of the Java monitor will bring extra overhead when thread contention gets higher. Currently, we have identified five drawbacks of the Java monitor. In this paper, we will first analyze these drawbacks in depth, and then propose a new monitor-based synchronization mechanism called EMonior. It has better expressive power, and introduces fewer overheads than the Java monitor when contention occurs. EMonior uses a preprocessor to translate the Java programs containing EMonitor syntax to regular Java programs that invoke EMonitor class libraries. It is very suitable to replace the Java monitor with the EMonitor when developing elaborate concurrent objects or high-contention concurrent systems.
A novel wafer reclaim method for silicon carbide film
(2003)
Tsui, BY
;
Fang, KL
;
Wu, CH
;
Li, YH
;
電子工程學系及電子研究所
As feature size keeps shrinking down, it is expected that amorphous SiC will replace Si3N4 in the Cu dual-damascene structure soon. SiC is chemically inert and is hard to be etched by wet processing. This property become adverse effect from the wafer reclaiming point of view. In this work, a novel wafer reclaiming method of oxidation followed by HF etching is proposed. Comparing with traditional reclaim method of wafer polish, this novel method exhibits great benefits of low cost, high throughput, and almost unlimited reclaim times.
A quantum trap MONOS memory device using AlN
(2006)
Lai, CH
;
Wu, CH
;
Chin, A
;
Wang, SJ
;
McAlister, SP
We report a IrO2-HfAlO-AlN-SiO2-Si MONOS device that displays excellent characteristics in terms of speed (100 mu s at +/- 13 V for program/erase) and memory window (3.7 V) at 85 degrees C operation. This device also shows good 10-year extrapolated data retention with a large 1.9 V window at 85 degrees C. The achieved performance compares well with the best reported memory device data. (c) 2006 The Electrochemical Society.
An investigation of quantum states in ultra-small InAs/GaAs quantum dots by means of photoluminescence
(2005-08-01)
Wu, CH
;
Lin, YG
;
Tyan, SL
;
Lin, SD
;
Lee, CP
The quantum states of InAs/GaAs quantum dots (QDs) with a base length of less than 10 nm are studied by means of excitation and temperature dependent photoluminescence (PL). The base length of the QDs, calculated by the PL ground state transition energy, is in agreement with the atomic force microscopy measurements. By means of the excitation-dependent PL, we demonstrate that only the ground electron and hole states exist when the base length of the QDs is smaller than about 7.3 nm, whereas larger dots, with a base length of about 8.7 nm, give rise to one excited hole state. The measured energy separation between the ground and the excited hole states is in good agreement with the theoretical calculation. The transition energy in the temperature-dependent PL spectra shows a rapid redshift as the temperature is raised higher than the critical temperature. The redshift rate is about 2.8 and 2.5 times larger than the values calculated by Varshni's law for small and large dots, respectively. The higher redshift rate can be explained by the stronger tunneling effect. In addition, the PL linewidths show a V-shaped dependence on the temperature. This behavior can be described as a tunneling and electron-phonon scattering effect.
Chinese handwritten character segmentation in form documents
(1999)
Chen, JL
;
Wu, CH
;
Lee, HJ
;
資訊工程學系
;
Department of Computer Science
This paper presents a projection based method for segmenting handwritten Chinese characters in form documents with known structures. In the preprocessing phase, a noise removal method is proposed that preserves stroke connections and character edge points. In the character segmentation phase, the projection profile analysis method is used to segment a text line image into projection blocks. In addition, projection blocks are classified into one of four types: mark, half-word, single-word, and two-word. Large blocks are then split and small blocks are merged. In addition, an OCR system is adopted to eliminate errors resulting from the inappropriate merging of Chinese numerical characters with other characters. As for 1319 Chinese characters are tested during our experiments, the correct segmentation rates of 92.34% and 91.76% are obtained with and without the OCR module.
Design of a concurrent dual-band receiver front-end in 0.18um CMOS for WLANs IEEE 802.11a/b/g applications
(2004)
Jou, CF
;
Cheng, KH
;
Lien, WC
;
Wu, CH
;
Yen, CH
A fully monolithic dual-band concurrent receiver chip for IEEE 802.11 a, 802.11 b and 802.11 g applications is presented in a 0.18-mum CMOS 1P6M technology. A low IF architecture was chosen in order to achieve a low-cost and low-power solution with a high level of integration compared to direct conversion architecture. This mixer can operate as a sub-harmonic mixer and even as a traditional Gilbert mixer if LO ports connecting to each other to found two RF inputs and two LO inputs. For a 1.8V power supply, the overall power consumptions are 84.3 mW, with 3.5 dB and 6.3 dB overall receive-chain noise figure for 2.45 GHz and 5.25 GHz, respectively.
Fully silicided NiSi and germanided NiGe dual gates on SiO2 n- and p-MOSFETs
(2003-12-01)
Yu, DS
;
Wu, CH
;
Huang, CH
;
Chin, A
;
Chen, WJ
We have fabricated the fully silicided NiSi and germanided NiGe dual gates n- and p-MOSFETs on 1.9 nm thick SiO2 gate dielectric. The extracted work functions of fully NiSi and NiGe gates from thickness-dependent flat band voltage were 4.55 and 5.2 eV respectively, which may provide possible wide work function tuning using NiSi1-xGex. In additional to the lower gate current than Al gate n- and p-MOSFETs, the fully silicided NiSi and germanided NiGe gates MOSFETs show electron and hole mobilities close to universal mobility values with special advantage of process compatible to current VLSI fabrication line.
Fully silicided NiSi and germanided NiGe dual gates on SiO2/Si and Al2O3/Ge-on-insulator MOSFETs
(2003)
Huang, CH
;
Yu, DS
;
Chin, A
;
Wu, CH
;
Chen, WJ
We demonstrate for the first time fully silicided NiSi (4.55eV) and germanided NiGe (5.2eV) dual gates on 1.9nm-SiO2/Si and Al2O3/Ge-On-Insulator (GOI) MOSFETs (EOT = 1.7nm). In additional to the comparable gate current and time-to-breakdown with AI gate C-MOSFETs, the fully NiSi and NiGe gates on SiO2/Si show mobility close to universal mobility while on Al2O3/GOI show similar to2.0X higher peak electron and hole mobility than Al on Al2O3/Si with special advantage of NiSi and NiGe compatible to current VLSI process line.
HfAlON n-MOSFETs incorporating low-work function gate using ytterbium silicide
(2006-06-01)
Wu, CH
;
Hung, BF
;
Chin, A
;
Wang, SJ
;
Yen, FY
The authors have fabricated low-temperature fully silicided YbSi2-x-gated n-MOSFETs that used an HfAION gate dielectric with a 1.7-nm EOT. After a 600 degrees C rapid thermal annealing, these devices displayed an effective work function of 4.1 eV and a peak electron mobility of 180 cm(2)/V(.)s. They have additional merit of a process compatible with current very large scale integration fabrication lines.
High hole mobility of Al2O3 mosfets on dislocation free Ge-on-insulator wafers
(2004)
Chin, A
;
Yu, DS
;
Wu, CH
;
Huang, CH
;
Chen, WJ
The much degraded mobility, high-kappa dielectric crystallization, and EOT reduction after processing are the primary limitations of high-kappa gate dielectric MOSFETs. We have fabricated the high-kappa Al2O3 MOSFET on Geon-Insulator to enhance the hole mobility. The measured hole mobility with 1.7 nm EOT is 73 cm(2)/Vs at E-eff of 1 MV/cm, which is 2.5 times and 1.3 times higher than and Al2O3/Si control devices and SiO2/Si universal mobility, respectively. In additional to good dielectric reliability, the low temperature process (less than or equal to500degreesC) can also avoid high-kappa dielectric crystallization and EOT reduction by O-2 or moisture penetration through high-kappa dielectric.
High work function IrxSi gates on HfAlON p-MOSFETs
(2006-02-01)
Wu, CH
;
Yu, DS
;
Chin, A
;
Wang, SJ
;
Li, MF
We have fabricated the fully silicided IrxSi-gated p-MOSFETs on HfAlON gate dielectric with 1.7-mn equivalent oxide thickness. After 950 degrees C rapid thermal annealing, the fully IrxSi/HfAlON device has high effective work function of 4.9 eV, high peak hole mobility of 80 cm(2)/V.s, and the advantage of being process compatible to the current VLSI fabrication line.
Lanthanide and Ir-based dual metal-gate/HfAlON CMOS with large work-function difference
(2005)
Yu, DS
;
Chin, A
;
Wu, CH
;
Li, MF
;
Zhu, C
Metallic diffusion through high-K HfO(2), caused by high temperature metal-nitride decomposition, was reduced by using robust HfAlON. Useful dual effective work-function (phi(m,eff)) of 4.25 and 5.15 eV are obtained in TaTb(0.2)N/HfAlON and Ir/HfAlON at 1.7nm EOT. Good dual phi(m,eff) of 4.15 and 4.9 eV are also obtained in Yb(x)Si/HfAlON and Ir(x)Si/HfAlON FUSI-gates by reduced metal diffusion at lower temperature.
Multilevel recording in erasable phase-change media by light intensity modulation
(2001-03-01)
Shieh, HPD
;
Chen, YL
;
Wu, CH
;
光電工程學系
;
Department of Photonics
Multilevel recording has an advantage of increasing the recording density without extensively altering the current optical configuration. Four-level recording schemes in phase-change disks using either two or three recording layers were demonstrated. By modulating the intensity of the laser pulse, marks were recorded in any of the recording layers, forming four recording regions. Utilizing the large difference in refractive indices between the amorphous and crystalline states, each recording region corresponds to a different reflectance. For the four-level recording disk, if each recording region represents two-bit data, then the recording density of the four-level disk can be higher by a factor of two than that of a conventional disk recorded by pulse position modulation (PPM).
Parallel synthesis of amino bis-benzimidazoles by multistep microwave irradiation
(2006-04-10)
Wu, CH
;
Sun, CM
;
應用化學系
;
Department of Applied Chemistry
A multistep liquid phase synthesis of specifically functionalized bis-benzimidazoles is presented by the application of single-mode microwave irradiation technique. The sustained solubilizing power and stability of the PEG-ester derived from the commercially available 4-fluoro-3-nitrobenzoic acid has been successfully carried through 10 steps involving iPSO-SNAr reaction, neutral reduction and acid cyclization. All the steps in this synthetic sequence were assisted by microwave (MW) irradiation. The polymer support was cleaved to release the final head to tail bisbenzimidazoles in an efficient process. (c) 2006 Elsevier Ltd. All rights reserved.
Photoluminescence of ultra small InAs/GaAs quantum dots
(2005-08-10)
Lin, YG
;
Wu, CH
;
Tyan, SL
;
Lin, SD
;
Lee, CP
The InAs/GaAs quantum dots (QDs) with a baselength of less than 10 nm are studied by the excitation-, temperature-dependent and magneto-photoluminescence (PL). The baselengths of the QDs, calculated by the PL ground state transition energy and estimated by magneto-PL spectra, axe in agreement with the result of atomic force microscopy measurements. By means of the excitation-dependent PL, we demonstrate that only the ground electron and hole states exist when the baselength of the QDs is smaller than about 7.3 nm, whereas the larger dots with a baselength of about 8.7 nm will give rise to one excited hole state. The measured energy separation between the ground and the excited hole states is in good agreement with the theoretical calculation. The transition energy in temperature-dependent PL spectra shows a rapid redshift as the temperature is higher than the critical temperature. The redshift rate is about 2.8 and 2.5 times larger than the values calculated by Varshni's law for small and large dots respectively. The higher redshift rate can be explained by the stronger tunneling effect. In addition, the PL linewidths show a V-shape dependence with the temperature. This behavior could be well described as a tunneling and electron-phonon scattering effect.
Poly(phenyl acrylate) and Poly(p-methylphenyl acrylate) as photo-stabilizers II. Protection of PET against photo-oxidation
(2004-03-01)
Lee, CT
;
Wu, CH
;
Lin, MS
;
應用化學系
;
Department of Applied Chemistry
Poly(phenyl acrylate) (PPA) and poly(p-methylphenyl acrylate) (PMPA) were used as inherent photo-stabilizers for PET. PPA/ PET and PMPA/PET in weight ratios of 0/100, 5/95, 10/90, 20/80 and 100/0 were blended. These blends were then cast into films and drawn into fibres and were irradiated with an accelerated weathering tester (QUV). Functional group changes in the films during irradation were monitored with FTIR and the absorbance changes for different samples were compared with one another. Tensile strength of fibres after 42 days of irradiation were tested. Experimental results revealed that when 5% of PPA or PMPA was incorporated into PET, good stabilization of the film and fibres were observed, with PMPA exhibiting more photo-stabilization capability and better retention of tensile strength after 42 days of accelerated aging. (C) 2003 Elsevier Ltd. All rights reserved.
Role of haptoglobin in formation of atherosclerosis
(2001-03-07)
Mao, SJT
;
Yang, SJ
;
Wu, CH
;
交大名義發表
;
National Chiao Tung University
Selective deposition of gold particles on dip-pen nanolithography patterns on silicon dioxide surfaces
(2006-04-01)
Sheu, JT
;
Wu, CH
;
Chao, TS
;
材料科學與工程學系奈米科技碩博班
;
電子物理學系
We report a novel platform to perform selective deposition of gold nanoparticles on dip-pen nanolithographic patterns on SiO2 surfaces. An "inked" atomic force microscope (AFM) tip was adopted to deposit 2.2mM organic N-(2-aminoethyl)-3aminopropyltriniethoxysilane (AEAPTMS) Molecules in nanopatterns through a water meniscus onto a SiO2, substrate under ambient conditions; the molecules act as linkers for the selective deposition of gold nanoparticles on the SiO2 surface. Conditions for dip-pen nanolithography of organic nanopatterns of AEAPTMS were investigated. In addition, gold nanoparticles with negatively-charged citrate Surfaces were deposited selectively on top of the organic patterns. X-ray photoelectron spectroscopy was then used to evaluate the presence of gold nanoparticles on the SiO2 surface. Lateral force microscopy was utilized to differentiate the surface between oxidized semiconductors and patterned areas with monolayer of AEAPTMS. Linewidths down to 60 nm have been successfully achieved by this method.
Single-crystal silicon nanostructure fabrication by scanning probe lithography and anisotropic wet etching
(2001)
Chang, KM
;
You, KS
;
Wu, CH
;
Sheu, JT
;
電子工程學系及電子研究所
Silicon nanostructures have been demonstrated by electric-field-enhanced localized oxidation on single crystal silicon wafer using a scanning probe microscope (SPM). In this study, we have demonstrated the use of scanning probe lithography (SPL) and orientation-dependent etching (ODE) can easily obtain nano-wire and nano-gap down to 24nm and 60nm on (110)-oriented silicon substrate. The scanning probe lithography (SPL) provides high resolution, which can be adjusted by tip bias, tip set force, scanning speed, and ambient humidity of environment, without damage in the substrate. The etching process employed the orientation-dependent etching (ODE), because of the etching rate of the (Ill)-plane is slower than any other crystallographic planes such that anisotropic etching profile can be obtained. The experimental samples were hydrogen-passivated by dipping in 10% aqueous HF solution to remove sample native oxide on the surface before SPM localized oxidation process. The SiOx nano-patterns on (110)-oriented silicon substrate were generated by SPM localized oxidation. Then, the etching process employed the ODE with a 34 wt.% aqueous KOH solution. The nano-wire feature size is easily down to 24nm and aspect ratio larger than 4:1. The optimization fine/space nanostructure is about 20 nm/80 nm and the nano-gap is about 60nm. In this study, we also have demonstrated the influence of etching temperature on the feature size of nanostructures with same aspect ratio. At the same etching depth (100nm), the line-width decreases with increasing the etching temperature. The theoretic etching rate and experimental etching rate are proportional to temperature, the higher temperature the higher etching rate.
Single-electron transistor structures based on silicon-on-insulator silicon nanowire fabrication by scanning probe lithography and wet etching
(2002-11-01)
Sheu, JT
;
You, KS
;
Wu, CH
;
Chang, KM
;
電子工程學系及電子研究所
We propose a promising fabrication technology for single-electron transistors based on a silicon-on-insulator (SOI) nanowire fabricated by scanning probe lithography and KOH wet etching. The 10-nm-wide and 10-nm-high silicon nanowire is defined by scanning probe lithography and KOH wet etching process technology. Along the [100] direction on a (100) SOI silicon wafer, local oxidation was performed in ambient using highly doped Si cantilevers with a resistivity of 0.01-0.0025 Omega cm and a commercial atomic force microscope/scanning tunneling microscope instrument. Using the oxide pattern as a Si etching mask, the Si substrate was dipped in aqueous KOH solution, in which unoxidized regions are selectively etched by aqueous KOH orientation-dependent etching. The silicon nanowire was obtained by well-controlled overetching of 34 wt % at 40 degreesC for 50 s. The top gate, back gates and contact pads were defined by photolithography and dry etching. Statistics showing the reproducibility of this technique are also demonstrated. (C) 2002 American Vacuum Society.