Analytical base transit time model of uniformly doped base bipolar transistors considering Kirk effect

Abstract

In this paper analytical expressions of effective base width and base transit time for uniformly doped base of bipolar junction transistors (BJT) are developed taking Kirk effect into consideration. Modern bipolar junction transistors tend to operate with saturated carrier velocity in the collector space-charge region, and therefore we have incorporated this effect in the present work. Physical analysis of Kirk effect shows that the base transit time increases significantly when the base width widening or when Kirk effect is considered.