Current-voltage characteristics of bipolar transistors including quasi-saturation, finite collector lifetime, and high-low junction effects

Abstract

Abstract A physics-based and compact model is developed to predict the bipolar transistor DC characteristics covering all saturation, quasi-saturation, and active operations. The present model differs from the existing models in that the present model employs a regional approach rather than the charge-control approach used previously and that the present model requires only the physical parameters, such as device make-up, whereas the previous models often require parameters extracted from measurements. Device physics relevant to the base-collector junction, like current-induced base widening and conductivity modulation and electron-hole recombination in the quasi-neutral collector layer, are accounted for in the analysis. We show that the current-voltage characteristics predicted by the present model compare favourably with that obtained from measurements and simulations reported in the literature.