Collector optimization for tradeoff between breakdown voltage and cut-off frequency in SiGe HBT

As is well known, there exists a tradeoff between the breakdown voltage BVcEO and the cut-off frequency fT for a standard heterojunction bipolar transistor （HBT）. In this paper, this tradeoff is alleviated by collector doping engineering in the SiGe HBT by utilizing a novel composite of P＋ and N- do...

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Published inChinese physics B Vol. 23; no. 11; pp. 354 - 358
Main Author 付强 张万荣 金冬月 丁春宝 赵彦晓 鲁东
Format Journal Article
LanguageEnglish
Published 01.11.2014
Subjects
Accumulators
Collectors
Cut-off
Doping
Electric potential
Electrical junctions
HBT
Metallurgy
SiGe
Silicon germanides
Voltage
优化
击穿电压
异质结双极晶体管
截止频率
收藏家
权衡
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ISSN1674-1056
2058-3834
1741-4199
DOI10.1088/1674-1056/23/11/114402

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Summary:As is well known, there exists a tradeoff between the breakdown voltage BVcEO and the cut-off frequency fT for a standard heterojunction bipolar transistor （HBT）. In this paper, this tradeoff is alleviated by collector doping engineering in the SiGe HBT by utilizing a novel composite of P＋ and N- doping layers inside the collector-base （CB） space-charge region （SCR）. Compared with the single N-type collector, the introduction of the thin P＋ layers provides a reverse electric field weakening the electric field near the CB metallurgical junction without changing the field direction, and the thin N layer further effectively lowers the electric field near the CB metallurgical junction. As a result, the electron temperature near the CB metallurgical junction is lowered, consequently suppressing the impact ionization, thus BVcEO is improved with a slight degradation in fT. The results show that the product of fTXBVcEo is improved from 309.51 GHz.V to 326.35 GHz.V.
Bibliography:Fu Qiang, Zhang Wan-Rong, Jin Dong-Yue, Ding Chun-Bao, Zhao Yan-Xiao, and Lu Dong（ a） College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 1 O0124, China b） College of Physics, Liaoning University, Shenyang 110036, China
SiGe heterojunction bipolar transistors （HBTs）, breakdown voltage, cut-off frequency, collectoroptimization
As is well known, there exists a tradeoff between the breakdown voltage BVcEO and the cut-off frequency fT for a standard heterojunction bipolar transistor （HBT）. In this paper, this tradeoff is alleviated by collector doping engineering in the SiGe HBT by utilizing a novel composite of P＋ and N- doping layers inside the collector-base （CB） space-charge region （SCR）. Compared with the single N-type collector, the introduction of the thin P＋ layers provides a reverse electric field weakening the electric field near the CB metallurgical junction without changing the field direction, and the thin N layer further effectively lowers the electric field near the CB metallurgical junction. As a result, the electron temperature near the CB metallurgical junction is lowered, consequently suppressing the impact ionization, thus BVcEO is improved with a slight degradation in fT. The results show that the product of fTXBVcEo is improved from 309.51 GHz.V to 326.35 GHz.V.
11-5639/O4
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SourceType-Scholarly Journals-1
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content type line 23
ISSN:1674-1056
2058-3834
1741-4199
DOI:10.1088/1674-1056/23/11/114402