Optimization and temperature dependence of current gain in polysilicon-emitter-contacted bipolar transistors

Presented herein are the results of an experimental and theoretical investigation of the factors influencing the current gain of a polysilicon-emitter-contacted bipolar transistor (PEC transistor). Specifically, the temperature behavior of gain and its optimization are comprehensively discussed. The results show that the PEC transistor exhibits a stronger temperature dependence when compared with conventional transistors. This is attributed to the diffusion length of minority carriers (holes) in the polysilicon. The modeling of the gain ( h_fe) reveals that the mobility and the recombination lifetime of the minority carriers in the polysilicon are the key parameters for optimizing h_fe in PEC transistors