Modeling the small-emitter effect in polysilicon-emitter transistors

Abstract

Arsenic shadowing, which is an important consideration for the small-emitter effect in bipolar polysilicon-emitter transistors, was simulated using two-dimensional process and device modeling tools. Results are compared with data for conventional and epi-base polysilicon-emitter technologies. Consideration is also given to other parameters that affect the base current. This analysis shows that the principle features of the arsenic shadowing effect can be modeled and explained by using the simulation tools. These simulations showed that the small-emitter effect was still present in the more advanced epi-base devices.<>