A reverse base current under high level injection and its influence on BiCMOS circuit

Abstract

The base pushout induced reverse base current (I/sub RB/) at high level injection was observed and analyzed. A simple model to describe this phenomenon was also proposed. The I/sub RB/ is described universally by this model even if collector conditions are varied. The I/sub RB/ increases with decreasing device temperature and is suppressed by voltage drop at the external base region due to carrier freeze-out. This reverse base current causes failure on the BiCMOS circuit and gives a new limitation for applied power supply voltage.<>