基区重掺杂对SiGe HBT热学性能的影响  

Effect of Base Heavy Doping on Thermal Characteristic of SiGe HBT

作　　者：付强[1] 张万荣 金冬月[1] 谢红云[1] 赵昕[1] 王任卿[1] 

机构地区：[1]北京工业大学电子信息与控制工程学院,北京100124

出　　处：《半导体技术》2011年第4期261-264,共4页Semiconductor Technology

基　　金：国家自然科学基金(60776051;60376033;61006059;61006044);北京市自然科学基金项目(4082007);北京市教委科技发展计划项目(KM2007010005015;KM200910005001)

摘　　要：相对于同质结晶体管,异质结双极晶体管(HBT)由于异质结的存在,电流增益不再主要由发射区和基区掺杂浓度比来决定,因此可以通过增加基区掺杂浓度来降低基区电阻,提高频率响应,降低噪声系数,但基区掺杂浓度对器件热特性影响的研究却很少。以多指SiGeHBT的热电反馈模型为基础,利用自洽迭代法分析了基区重掺杂对器件集电极电流密度和发射极指温度的影响。通过研究发现,随着基区浓度的增加,SiGe HBT将发生禁带宽度变窄,基区反向注入发射区的空穴电流增大;同时,基区少子俄歇复合增强,这些都将减小集电极电流密度,降低发射极指温度,从而抑制发射极指热电正反馈,提高器件的热稳定性。Compared to homojunction transistors, because of heterojunction existence, the current gain of SiGe heterojunction bipolar transistor （HBT） is not mainly determined by the ratio of emitter doping to base doping. Therefore, base doping can be increased to decrease base resistance, increase frequency response and decrease noise coefficient. However, the effect of base doping on thermal characteristic of SiGe HBT is researched rarely. Based on the electro-thermal feedback model for multifinger power SiGe HBT, the effect of base heavy doping on the collector current density and the emitter finger temperature were analyzed by using self-consistent calculation iteration. As base doping increases, SiGe HBT will produce bandgap narrowing, and the base hole current which injects reversely into the emitter will enhance, and the base minority carrier Auger recombination will enhance. Those will eventually decrease the collector current density and the emitter finger temperature, which restrains the emitter finger thermoelectric positive feedback and improves the device thermal stability.

关 键 词：SIGE异质结双极晶体管 基区重掺杂 热电正反馈 热学性能 掺杂浓度 

分 类 号：TN322.8[电子电信—物理电子学]