An accurate quasi-static method for determining the excess phase shift in the base region of bipolar transistors

Abstract

The conventional quasi-static approach has been extended to enable the accurate calculation of the phase shift of the common emitter current gain up to the transition frequency solely from static charge distributions for bipolar transistors with arbitrary base impurity profiles. Accurate knowledge of the phase shift allows the use of simple, yet accurate, high-frequency compact bipolar transistor models which use this information to determine critical model parameters. The accuracy of this approach was assessed by AC numerical simulation. The ability of the approach to estimate the phase shift of the common emitter current gain from static charge distributions allows accurate predictive high-frequency AC modeling of both digital and analog bipolar and BiCMOS circuits without the need for high-frequency, time-dependent device simulation or high-frequency device measurements.<>