Browsing by Author "Chen, Han-Yu"

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An analysis of base current effect on the anomalous dip of scattering parameter S(12) in SiGeHBTs
(2005)
Chen, Han-Yu
;
Chen, Kun-Ming
;
Huang, Guo-Wei
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
In this paper, the anomalous dip in scattering parameters S(12) of SiGe HBTs is explained quantitatively for the first time. It was found that under constant collector-emitter voltage (V(CE)), an increase of base current (which corresponds to an increase of base-emitter capacitance (C pi) enhances the anomalous dip.
Coordinated and Simultaneous Formation of Paired Ge Quantum Dots by Thermal Oxidation of Designer Poly-SiGe Spacer Structures
(2020-01-01)
Chen, Han-Yu
;
Peng, Kang-Ping
;
George, Thomas
;
Lin, Horng-Chih
;
Li, Pei-Wen
We report a novel self-organized approach for the controllable placement of paired Ge quantum dots (QDs) along each sidewall edge of poly-Si ridges by simply thermally oxidizing spacer layers of poly-SiGe and Si3N4 that conformally encapsulate the poly-Si ridges. Additionally, controllable diameters ranging from 20-50 nm and precise location of paired Ge QDs are enabled by adjusting the thickness of poly-SiGe spacer layers in combination with specific processing conditions. These conditions include the subsequent lithographic patterning through direct etch-back for forming spacer stripes and spacer islands. The spacing between paired Ge QDs across the ridge is essentially determined by the width of the patterned poly-Si ridge. Inter-QD spacings along the sidewall of the poly-Si ridge are a consequence of heterogeneous nucleation and Ostwald Ripening.
Impact of Body Bias on the High Frequency Performance of Partially Depleted SOI MOSFETs
(2008)
Huang, Guo-Wei
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Chen, Kun-Ming
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Chen, Han-Yu
;
Huang, Chi-Huan
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Chang, Chun-Yen
RF Noise Modeling of SiGe HBTs Using Four-Port De-embedding Method
(2008)
Chen, Kun-Ming
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Chen, Han-Yu
;
Huang, Guo-Wei
;
Liao, Wen-Shiang
;
Chang, Chun-Yen
Small-signal modeling of SiGeHBTs using direct parameter-extraction method
(2006-09-01)
Chen, Han-Yu
;
Chen, Kun-Ming
;
Huang, Guo-Wei
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
A simple and accurate parameter-extraction method of a high-frequency small-signal SiGe heterojunction bipolar transistor model is proposed in this paper. It was found that, without taking the intrinsic circuit elements into account, the conductance of the substrate network will be underestimated, while the susceptance of the substrate network will be overestimated. Therefore, a new extraction technique of the substrate-network parameters was developed, which has taken the intrinsic circuit elements into consideration. Transforming the intrinsic equivalent circuit into its common-collector configuration, all the intrinsic circuit elements are extracted directly from the measured S-parameters without any numerical optimization. Two formulas used to determine the intrinsic base resistance are presented, which is followed by an accuracy-improvement procedure to achieve a better accuracy of the extraction results. Simplified formulas to determine the base-emitter resistance, base-emitter capacitance, transconductance, and excess phase delay are also presented. The proposed method is validated with SiGe HBTs fabricated with a 0.35-mu m BiCMOS technology from 1 to 30 GHz. The agreements between the measured and modeled data are excellent in the desired frequency range over a wide range of bias points.