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Your search keyword '"Kyungho Lee"' showing total 5 results
Start Over Author "Kyungho Lee" Journal ieee transactions on electron devices
5 results on '"Kyungho Lee"'

1. Direct parameter extraction of SiGe HBTs for the VBIC bipolar compact model

Author

Kyungho Lee, Kwangsik Choi, Sang-Ho Kook, Dae-Hyung Cho, Kang-Wook Park, and Kim, Bumman

Subjects
Bipolar transistors -- Design and construction, Circuit design -- Analysis, Germanium -- Electric properties, Silicon compounds -- Electric properties, Circuit designer, Integrated circuit design, Business, Electronics, Electronics and electrical industries
Abstract

An improved direct parameter extraction method of SiGe heterojunction bipolar transistors (HBTs) for the vertical bipolar intercompany (VBIC)-type hybrid-pi model is developed. This extraction method is a simple and reliable routine applicable to the optimization of transistor design, process control and the improvement of VBIC compact model, especially for SiGe HBTs.

Published
2005

2. New collector undercut technique using a SiN sidewall for low base contact resistance in InP/InGaAs SHBTs

Author

Kyungho Lee, Minchul Chung, Daekyu Yu, Jongchan Kang, and Bumman Kim

Subjects
Bipolar transistors -- Electric properties, Circuit design -- Testing, Gallium arsenide semiconductors -- Electric properties, Circuit designer, Integrated circuit design, Business, Electronics, Electronics and electrical industries
Abstract

A new collector undercut process using SiN protection sidewall is developed for high-speed InP/InGaAs single heterojunction bipolar transistor (HBTs). The result clearly shows the effectiveness of this technique for high-speed HBT process, especially for the HBTs with a thick collector layer, and narrow base metal width.

Published
2002

3. Improved VBIC model for SiGe HBTs with an unified model of heterojunction barrier effects

Author

Bumman Kim, Kang-Wook Park, Dae-Hyung Cho, and Kyungho Lee

Subjects
Materials science, Kirk effect, business.industry, Bipolar junction transistor, Direct current, Electrical engineering, Heterojunction, Transit time, Unified Model, Cutoff frequency, Electronic, Optical and Magnetic Materials, Optoelectronics, Electrical and Electronic Engineering, business, Saturation (magnetic)
Abstract

An improved bipolar transistor model considering heterojunction barrier effect (HBE) in SiGe double heterojunction bipolar transistors is developed. The effect of barrier formation due to high level injection, which is related to the rapid degradations of the dc current gain (/spl beta/) and cutoff frequency (f/sub T/), is carefully investigated and analyzed. As the collector current becomes high, the conduction band barrier is induced and increased. It causes the saturation of collector current (J/sub C/) due to the blocking of carrier transport, the sharp increase of base transit time (/spl tau//sub B/) due to the additional charge storage, the increase of base current (J/sub B/) due to the increased recombination, and the decrease of intrinsic base resistance (R/sub bi/) due to the increased charge and base pushout. Those phenomena are included into a vertical bipolar intercompany model (VBIC) compact model by employing a unified model of the HBE on J/sub C/, J/sub B/, /spl tau//sub B/, and R/sub bi/. Furthermore, portions of /spl tau//sub B/ and R/sub bi/ from the Kirk effect itself are modeled according to the high current model description and the new formulation of widened base, respectively. A full extraction of parameters has been performed and the modified VBIC model is applied. The modeling accuracy is significantly improved at the high current region for the dc and RF characteristics.

Published
2006

4. New collector undercut technique using a SiN sidewall for low base contact resistance in InP/InGaAs SHBTs

Author

Minchul Chung, Bumman Kim, Jongchan Kang, Daekyu Yu, and Kyungho Lee

Subjects
Materials science, business.industry, Heterojunction bipolar transistor, Contact resistance, Bipolar junction transistor, Electrical engineering, Heterojunction, Capacitance, Electronic, Optical and Magnetic Materials, Optoelectronics, Undercut, Electrical and Electronic Engineering, business, Contact area, Current density
Abstract

A new collector undercut process using SiN protection sidewall has been developed for high speed InP/InGaAs single heterojunction bipolar transistors (HBTs). The HBTs fabricated using the technique have a larger base contact area, resulting in a smaller DC current gain and smaller base contact resistance than HBTs fabricated using a conventional undercut process while maintaining low C/sub bc/. Due to the reduced base contact resistance, the maximum oscillation frequency (f/sub max/) has been enhanced from 162 GHz to 208 GHz. This result clearly shows the effectiveness of this technique for high-speed HBT process, especially for the HBTs with a thick collector layer, and narrow base metal width.

Published
2002

5. Improved VBIC Model for SiGe HBTs With an Unified Model of Heterojunction Barrier Effects.

Author

Kyungho Lee, Dae-Hyung Cho, Kang-Wook Park, and Bumman Kim

Subjects
*SEMICONDUCTOR junctions, *BIPOLAR transistors, *INTEGRATED circuits, *DIRECT current circuits, *SEMICONDUCTOR diodes, *SILICON compounds
Abstract

An improved bipolar transistor model considering heterojunction barrier effect (HBE) in SiGe double heterojunction bipolar transistors is developed. The effect of barrier formation due to high level injection, which is related to the rapid degradations of the dc current gain (β) and cutoff frequency (ƒT), is carefully investigated and analyzed. As the collector current becomes high, the conduction band barrier is induced and increased. It causes the saturation of collector current (JC) due to the blocking of carrier transport, the sharp increase of base transit time (τB) due to the additional charge storage, the increase of base current (JB) due to the increased recombination, and the decrease of intrinsic base resistance (Rbi) due to the increased charge and base pushout. Those phenomena are included into a vertical bipolar intercompany model (VBIC) compact model by employing a unified model of the HBE on JC, JB, τB, and Rbi. Furthermore, portions of τB and Rbi from the Kirk effect itself are modeled according to the high current model description and the new formulation of widened base, respectively. A full extraction of parameters has been performed and the modified VBIC model is applied. The modeling accuracy is significantly improved at the high current region for the dc and RF characteristics. [ABSTRACT FROM AUTHOR]

Published
2006
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