Electron trapping, nitride conduction, and forward gain instability in a lateral p-n-p device

The increase in the forward gain of a lateral p-n-p device under forward-bias stress conditions is discussed. The phenomenon has been characterized as a function of collector-base voltage, emitter current, and stress temperature. The results are interpreted as electron trapping at the interface between the passivation oxide and a silicon nitride overlayer. The trapping behavior is further modified by the finite conductivity of the silicon nitride. A quasi-empirical model for the effect incorporating the hot-electron injection and the nitride conduction has been developed