低温大注入多晶硅发射极硅双极晶体管电流增益的定量模拟

Quantitative Modeling of the Current Gain at High injection Levels inPolysilicon Emitter Contact Bipolar Transistor at Low Temperatures

已有的理论和实验都已证明，多晶硅发射极硅双极晶体管适合于低温工作。但至今为止，其完整的大注入时电流增益的理论分析还不成熟，特别是进行定量的计算；本文定量地模拟了低温７７Ｋ和常温３００Ｋ下多晶硅发射极硅双极晶体管电流增益与集电极电流密度的关系，并且分析了低温和常温下决定该晶体管电流增益大注入效应的主要物理效应，为低温多晶硅发射极硅双极晶体管的设计提供了有益的理论基础。

Existing experiments and theories have demonstrated that the polysilicon emitter contact bipolar transistor (PET) is suitable for the low temperature operation. However, an overall theory for the current gain of PET is still absent, particularly for the quantitative modeling at high injection levels. This paper presents the quantitative relationship between the current gain and the collector current density at both 77 K and 300 K. Besides, the main physical mechanisms for the current gain at high injection levels are also analyzed. These may provide a rational basis for the design of low temperature bipolar transistors.