Browsing by Author "Liu, J"

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40-GHz coplanar waveguide bandpass filters on silicon substrate
(2002-11-01)
Chan, KT
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Chen, CY
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Chin, A
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Hsieh, JC
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Liu, J
We report a very simple process to fabricate high performance filter on Si at 40 GHz; using proton implantation. The filter has only -3.4-dB loss at peak transmission of 40 GHz; with a broad 9-GHz bandwidth. In sharp contrast, the filter on 1.5-mum SiO2 isolated Si has much worse transmission and reflection loss. This is the first demonstration of high performance filter at millimeter-wave regime on Si with process compatible to current VLSI technology.
Analysis of the focal characteristics of cylindrical lenses made of anisotropically dielectric material based on rigorous electromagnetic theory
(2003-05-01)
Dong, BZ
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Ye, JS
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Liu, J
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Gu, BY
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Yang, GZ
The focal characteristics of refractive cylindrical lenses made of anisotropically dielectric material (uniaxial crystal) are analysed based on rigorous electromagnetic theory and the boundary element method. The performances of the lenses with different f numbers are appraised for both incident waves of the TE (transverse electric) and TM (transverse magnetic) polarizations. Numerical results show that the focal performance of this kind of lens for the TE polarization and the TM polarization of incident light wave is a difference, in particular, different focal lengths, owing to the anisotropy of the material. However, for the conventional isotropic lens, the focal features for both the TE and TM polarizations are the same. It is anticipated that this new kind of lens proposed for the first time may serve as a light switching device with high speed used in the micro-optical communication.
Formation of Ni germano-silicide on single crystalline Si0.3Ge0.7/Si
(2002-08-01)
Lin, CY
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Chen, WJ
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Lai, CH
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Chin, A
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Liu, J
We have studied the Ni and Co germano-silicide on Si0.3Ge0.7/Si. The Ni germano-silicide shows a low sheet resistance of 4-6 Omega/square on both P+N and N+P junctions, which is much smaller than Co germano-silicide. In addition, small junction leakage currents of 3 x 10(-8) A/cm(2) and 2 x 10(-7) A/cm(2) are obtained for Ni germano-silicide on P+ N and N+ P junctions, respectively. The good germano-silicide integrity is due to the relatively uniform thickness as observed by cross-sectional TEM.
Frequency-dependent capacitance reduction in high-k AlTiOx and Al2O3 gate dielectrics from IF to RF frequency range
(2002-04-01)
Chen, SB
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Lai, CH
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Chan, KT
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Chin, A
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Hsieh, JC
We have characterized the capacitance and loss tangent for high-k Al2O3 and AlTiOx gate dielectrics from IF (100 KHz) to RF (20 GHz) frequency range. Nearly the same rate of capacitance reduction as SiO2 was demonstrated individually by the proposed Al2O3 and AlTiOx gate dielectrics as frequency was increased. Moreover, both dielectrics preserve the higher k better than SiO2 from 100 KHz to 20 GHz. These results suggest that both Al2O3 and AlTiOx are suitable for next generation MOSFET application into RF frequency regime.
High-density MIM capacitors using Al2O3 and AlTiOx dielectrics
(2002-04-01)
Chen, SB
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Lai, CH
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Chin, A
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Hsieh, JC
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Liu, J
We have investigated the electrical characteristics of Al2O3 and AlTiOx MIM capacitors from IF (100 KHz) to RF (20 GHz) frequency range. Record high capacitance density of 0.5 and 1.0 muF/cm(2) are obtained for Al2O3 and AlTiOx MIM capacitors, respectively, and the fabrication process is compatible to existing VLSI backend integration. However, the AlTiOx MIM capacitor has very large capacitance reduction as increasing frequencies. In contrast, good device integrity has been obtained for Al2O3 MIM capacitor as evidenced from the small frequency dependence, low leakage current, good reliability, small temperature coefficient, and low loss tangent.
RF MIM capacitors using high-K Al2O3 and AlTiOx dielectrics
(2002)
Chen, SB
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Lai, CH
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Chin, A
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Hsieh, JC
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Liu, J
Record high capacitance density of 0.5 and 1.0 muF/cm(2) are obtained for Al2O3 and AlTiOx MIM capacitors respectively, with loss tangent < 0.01 and process compatible to existing VLSI back-end integration. However, the AlTiOx MINI capacitor has large capacitance reduction as increasing frequencies. In contrast, the Al2O3 MINI capacitor has good device integrity of low leakage current of 4.3x10(-8) A/cm(2), small frequency-dependent capacitance reduction, and good reliability.
RF noise characteristics of high-k AlTiOx and Al2O3 gate dielectrics
(2002-07-01)
Chen, SB
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Huang, CH
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Chin, A
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Lin, J
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Jou, JP
We have characterized the radio frequency (rf) noise in high-k Al2O3 and AlTiOx gate dielectrics, which have respective effective oxide thickness (EOT) of 17.2 and 12.5 Angstrom. The measured noise figure in gate dielectric is material dependent and sensitive to dielectric defect after stress. Although the high-k AlTiOx gate dielectric has lower EOT, it has a higher noise figure than others. From the simulation in our proposed equivalent circuit model, the dominant noise is thermal noise and the reason for increasing noise figure after stress is due to additional parallel resistance by trap-assisted tunneling. (C) 2002 The Electrochemical Society.
RF noise in 0.18-mu m and 0.13-mu m MOSFETs
(2002-12-01)
Huang, CH
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Lai, CH
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Hsieh, JC
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Liu, J
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Chin, A
We have studied the gate finger number and gate ength dependence on minimum noise figure (NFmin) in deep submicrometer MOSFETs. A lowest NFmin. of 0.93 dB is measured in 0.18-mum MOSFET at 5.8 GHz as increasing finger number to 50 fingers, but increases abnormally when above 50. The scaling gate length to 0.13 mum shows larger NFmin than the 0.18-mum case at the same finger number. From the analysis of a well-calibrated device model, the abnormal finger number dependence is due to the combined effect of reducing gate resistance and increasing substrate loss as increasing finger number. The scaling to 0.13-mum MOSFET gives higher NFmin due to the higher gate resistance and a modified T-gate structure proposed to optimize the NFmin for further scaling down of the MOSFET.
Using hypermedia in computer-aided instruction
(1996-05-01)
Chen, LS
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Liu, PW
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Chang, KY
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Chen, JP
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Chen, SC