基区不均匀重掺杂对Si/SiGe/SiHBT基区渡越时间的影响  

Effects of Nonuniform Heavy Doping in the Base on Base Transit Time of Si/SiGe/Si HBT’s

作　　者：张万荣 李志国[1] 孙英华[1] 程尧海[1] 陈建新[1] 沈光地[1] 

机构地区：[1]北京工业大学电子工程系,北京100022

出　　处：《微电子学》2000年第1期5-7,共3页Microelectronics

基　　金：北京市自然科学基金;北京市科技新星计划;电子元器件可靠性国家重点实验室资助课题

摘　　要：由于发射结(EB结)价带存在着能量差ΔEv,电流增益β不再主要由发射区和基区杂质浓度比来决定,给HBT设计带来了更大的自由度。为减小基区电阻和防止低温载流子冻析,可增加基区浓度。但基区重掺杂导致禁带变窄,禁带变窄的非均匀性产生的阻滞电场使基区渡越时间增加,退化了频率特性。The presence of valance bandgap discontinuity, Δ E v, at BE heterojunction gives greater design freedom for HBT’s, compared with BJT’s, because current gain is not determined mainly by the concentration ratio of the emitter to base.In order to reduce base resistance and mitigate carrier freeze out at low temperatures, the base concentration can be increased. However, the retarding field due to the nonuniform heavy doping bandgap narrowing increases base transit time, which degrades frequency performance, especially at low temperatures.

关 键 词：异质结晶体管 掺杂 基区渡越时间 硅 锗化硅 HBT 

分 类 号：TN322.8[电子电信—物理电子学]