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

作　　者：付强 张万荣 金冬月 丁春宝 赵彦晓 鲁东 

机构地区：[1]College of Electronic Information and Control Engineering, Beijing University of Technology [2]College of Physics, Liaoning University

出　　处：《Chinese Physics B》2014年第11期354-358,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.60776051,61006059,and 61006044);the Beijing Municipal Natural Science Foundation,China(Grant Nos.4142007,4143059,4082007,and 4122014);the Beijing Municipal Education Committee,China(Grant Nos.KM200710005015 and KM200910005001)

摘　　要：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.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.

关 键 词：SiGe heterojunction bipolar transistors （HBTs） breakdown voltage cut-off frequency collectoroptimization 

分 类 号：TN322.8[电子电信—物理电子学]