The role of the interfacial layer in polysilicon emitter bipolar transistors

This paper presents a unified theory for current transport in the monocrystalline emitter, thin oxide layer, and polycrystalline region of a bipolar transistor with a polysilicon emitter. The transport and tunneling equations are arranged in such a way that fast numerical solutions are readily obtained. A clear qualitative description is presented of the processes involved in gain determination and quantitative results are given for typical structures with various interfacial oxide layer thickness as a function of bias conditions.