The effects of collector lifetime on the characteristics of high-voltage power transistors operating in the quasi-saturation region

High-voltage power transistor operating in the quasi-saturation region is analyzed taking into account the effects of the injection of holes into the collector and the back injection of the electrons from the collector into the base. It is shown that the collector recombination lifetime τνplays an important role on the power transistor characteristics. Experimental results available in the literature on the output characteristics and the injection level dependence of current gain of transistors agree very well with the analysis presented in this paper. It is also shown that the hFEICproduct in the quasi-saturation region depends upon the collector region lifetime τν.