Browsing by Author "Ho, CC"

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0.13-mu m RF CMOS and varactors performance optimization by multiple gate layouts
(2004-12-01)
Ho, CC
;
Kuo, CW
;
Chan, Y
;
Lien, WY
;
Guo, JC
0.13-mum radio frequency (RF) CMOS devices with multifinger gate structure have been fabricated by the standard logic process, and the measured effective gate-length is 80 nm. Extensive RF characterization has been done to obtain cutoff frequency (f(T)), associated power gain cutoff frequency (f), minimum noise figure (NFmin), output power (P-out), and power added efficiency (PAE) for RF circuit design and to explore the optimized gate layout in terms of the extracted RF device parameters. Our important finding to be reported in this paper is that an optimized unit finger width (W-F) exists by trade-off among f(T), f(.max), NFmin, P-out, and PAE. Under fixed total width to achieve the same current drivability (I-ds), the smaller W-F and the larger finger number (N-F) leads to higher f(max) but lower f(T) due to trade-off between gate resistance (R-g) and parasitic gate capacitance. As for NFmin complicated by f(T) and R-g, counter-balance between parasitic gate capacitance and R-g leads to nearly constant NFmin. w.r.t. various splits of (W-F, N-F). Regarding P-out and PAE, W-F of 4 mum and NF of 18 is the optimized layout parameter, which offers the maximum P-out of around 11 dBm and PAE of 30.5% at 5.8 GHz. The performances of accumulation-mode MOS varactors with different gate layout structures are also investigated in this report. Since the same area varactors with different gate layout may result in different parasitic resistance and fringing capacitance, which will affect the capacitance tuning range and the associated Q-factor. The maximum Q-factor is about 59 of the 120 mum(2) gate area varactor, and its tuning range is from 210 IF to 1.64 pF, where the maximum C-max/C-min ratio is about 7.8.
Electromigration and integration aspects for the copper-SiLK system
(2004-07-01)
Tseng, HS
;
Chiou, BS
;
Wu, WF
;
Ho, CC
;
電子工程學系及電子研究所
In this study, the thermal characteristics and electromigration (EM) resistance of two dielectrics, SiLK(TM) and SiO2, are investigated to evaluate the feasibility of low dielectric-constant SiLK for intermetal. dielectric applications. Liftoff patterning was employed to fabricate the Cu interconnect for the EM test, and the Taguchi method was used in the experimental design to identify the key parameters for a successful liftoff. It was shown that the thermal impedance of the metal lines passivated with SiLK is 14% higher than that of metal lines passivated with SiO2. On the basis of the thermal impedance and temperature rise of the interconnect, it was concluded that the major heat transfer path is via the underlayer dielectric to the Si substrate. The activation energy of EM for Cu passivated with SiLK is smaller, and the EM lifetime is shorter than that of Cu passivated with SiO2. Possible mechanisms are discussed.
Face selectivity in the 1,3-dipolar cycloaddition reactions of benzonitrile oxide with 5-substituted adamantane-2-thiones and 2-methyleneadamantanes
(1997-07-11)
Chung, WS
;
Tsai, TL
;
Ho, CC
;
Chiang, MYN
;
leNoble, WJ
The 1,3-dipolar cycloaddition reactions of benzonitrile oxide with 5-substituted adamantane-2-thiones (2-X) and 2-methyleneadamantanes (3-X) produced two geometrically isomeric Delta(2)-1,4,2-oxathiazolines (5-Xs) and two Delta(2)-isoxazolines (6-Xs), respectively. The substituent was varied from fluoro, chloro, bromo, to phenyl. X-ray single-crystal analysis confirmed the configuration of (Z)-5-F. The produce formation bias resulting from the favored attack of nitrile oxide on the zu-face is discussed in terms of transition-state hyperconjugation and frontier molecular orbital theory.
Face selectivity in the photocycloaddition reactions of acrylonitrile to 5-substituted adamantan-2-ones and pyrolysis of the products to methyleneadamantanes
(1997-03-01)
Chung, WS
;
Ho, CC
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The photocycloaddition of acrylonitrile to 5-substituted adamantan-2-ones :(l-X) produces two geometrically isomeric oxetanes in which the oxygen atom and the 5-substituent are in the anti or syn positions, The substituent was varied from fluoro, chloro, bromo, hydroxy to phenyl and the product ratios were similar (ca, 60:40) in all instances, Small portions (<5%) of the oxetanes were pyrolysed when analysed by GC at above 200 degrees C, and the products from the pyrolysis were confirmed to be the corresponding methyleneadamantanes by independent syntheses, Assignment of the configuration of the oxetanes was found to be consistent with C-13 additivity scheme and the chemical shifts are more closely predicted using known oxetanes of l-X with methacrylonitrile. The product formation bias resulting from the attack on the syn-face can be explained using-the Cieplak transition state theory.
Mn,Cd-metallothionein-2: A room temperature magnetic protean
(2006-02-24)
Chang, CC
;
Lee, SF
;
Sun, KW
;
Ho, CC
;
Chen, YT
Naturally occurring metallothionein (MT) is a metal binding protein, which binds to seven Zn2+ through 20 conserved cysteines and forms two metal binding clusters with a Zinc-Blende structure. We demonstrate that the MT, when substituting the Zn2+ ions by Mn2+ and Cd2+, exhibits magnetic hysteresis loop observable by SQUID from 10 to 330 K. The magnetic moment may have originated from the bridging effect of the sulfur atoms between the metal ions that leads to the alignment of the electron spins of the Mn2+ ions inside the clusters. The protein backbone may restrain the net spin moment of Mn2+ ions from thermal fluctuation. The modified magnetic-metallothionein is a novel approach to creating molecular magnets with operating temperatures up to 330 K. (c) 2005 Elsevier Inc. All rights reserved.
Photochemistry of acetone in the presence of exocyclic olefins: An unexpected competition between the photo-Conia and Paterno-Buchi reactions
(1997-02-07)
Chung, WS
;
Ho, CC
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
When irradiated in the presence of several exocyclic olefins, acetone undergoes homoalkylation with the olefins to form a series of 4-cycloalkylbutan-2-ones (with quantum yields of 0.14 +/- 0.01) rather than exhibiting the expected Paterno-Buchi reaction; in contrast, the photolysis of perdeuteriated acetone gave both types of products.
Photochemistry of acetone in the presence of exocyclic olefins: An unexpected competition between the photo-Conia and Paterno-Buchi reactions
(1997-02-07)
Chung, WS
;
Ho, CC
;
應用化學系
;
Department of Applied Chemistry
When irradiated in the presence of several exocyclic olefins, acetone undergoes homoalkylation with the olefins to form a series of 4-cycloalkylbutan-2-ones (with quantum yields of 0.14 +/- 0.01) rather than exhibiting the expected Paterno-Buchi reaction; in contrast, the photolysis of perdeuteriated acetone gave both types of products.
S-parameters-based high speed signal characterization of Al interconnect on low-k hydrogen silsesquioxane-Si substrate
(2006-03-01)
Ho, CC
;
Chiou, BS
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
;
Department of Electronics Engineering and Institute of Electronics
The International Technology Roadmap for Semiconductors (ITRS) predicts that by 2010 over one billion transistors will be integrated into one chip [Semiconductor Industry Associations, International Technology Roadmap for Semiconductors, 2004. Available from: < http://pubic.itrs.net/Files/2004UpdateFinal/2004Update.htm >]. The interconnect system of this one billion transistor chip will provide the required high-speed signal and power to transmit each transistor on the chip. This system will deliver high frequency signals to various circuits, and the parasitic effects associated with interconnect will become evident and cannot be ignored. Small parasitic capacitance (C) between interconnect are required to reduce the crosstalk, power consumption, and RC delay associated with the metal interconnect system. Therefore, interconnect with low dielectric constant (k) materials is required. In this study, hydrogen silsesquioxane (HSQ) thin films prepared under various conditions are employed as the intermetal dielectric and the high frequency characteristics of Al-HSQ system are investigated and compared with those of Al-SiO2 system. The S-parameters of the Al interconnect are measured for insertion loss and crosstalk noise. The interconnect transmission parameters are extracted from the S-parameters. A figure of merit (FOM) is employed to evaluate the characteristics of the Al-HSQ system at high frequencies (100 MHz-20 GHz). It is found that Al interconnect with HSQ films annealed at 400 degrees C has an insertion loss of 1.64 dB/mm, a coupling of -13.3 2 dB at 20 GHz, and a propagation delay of 0.121 ps/mu m, while those of the PECVD SiO2 films are 2.01 dB/mm (insertion loss), -13.40 dB (coupling), and 0.149 ps/mu m (propagation delay). The Al-400 degrees C-annealed-HSQ system has better performance than the Al-SiO2 system does from 100 MHz to 20 GHz. However, specimens with 350 degrees C-annealed HSQ films or plasma-treated HSQ films exhibit larger insertion losses and higher crosstalk noises than those with PECVD SiO2 films do. Both annealing temperature and O-2 plasma treatment of the HSQ films affect the high frequency characteristics of the Al-HSQ system. (c) 2005 Elsevier B.V. All rights reserved.
The effect of In2O3 conductive coating on the luminescence and zeta potential of ZnS : Cu, Al phosphors
(2005)
Chang, CH
;
Chiou, BS
;
Chen, KS
;
Ho, CC
;
Ho, JC
Phosphors used in CRTs have been coated with In2O3 conductive layer derived from the hydrolysis of indium chloride. It was found that brightness of the phosphors rises initially with the amount of InCl3, reaches a maximum at 10 Wt-% InCl3 and then decreases when more InCl3 was added. With 10 wt.% InCl3 coating, the brightness of ZnS:Cu, Al phosphor increases by 24% at 800 V and I RA while very little changes were observed in the luminescent emission peak and CIE color loci. The luminescence decay times increase with the increase of the conductive coating. However, they are shorter than 0.7 mu s for samples with the amount of coating ranging from 0 to 20 wt.% InCl3 and are Suitable for display applications. Conductive coating affects the surface chemistry of the phosphor particles, enhances the zeta potential of ZnS:Cu, Al in IPA solution. and, consequently, increases the electrophoretic deposition rate of the phosphors onto substrate. The zeta potential of 10 wt.% InCl3 coated ZnS:Cu, Al in isopropyl alcohol solution is 32 mV as compared to 1.2 mV of that of the uncoated ZnS:Cu, Al. Besides, the electrophoretic deposition rate of the 10 wt.% InCl3 coated ZnS:Cu, Al (0.23 mg/s) is larger than that of the uncoated phosphor (0.17 mg/s). (c) 2005 Elsevier Ltd and Techna Group S.r.l. All rights reserved.