Low Frequency Noise in the Base Current of Polysilicon Emitter BJT´s after Hot-Carrier Stress

A simple model of the base current low frequency noise in a BiCMOS BJT´s is presented. This model accounts for the carrier number fluctuations which arise in the generation-recombination base current component from the trapping-detrapping processes occurring in the vicinity of oxide spacers. The model predicts reasonably well the power law dependence of the base current noise versus the base current before and after stress. Moreover, a quantitative analysis of the reverse-bias-stress-induced interface states responsible for an increase (decrease) of the base current (current gain) is also presented.