Monte Carlo analysis of ultrahigh-speed InP/InGaAs HBTs

Abstract

Research Center "MICROEL" Krasikov Str. 25a Moscow 11 7218, Russia KEY TERMS Heterojunction bipolar transistor, high-frequency performance, ensemble Monte Carlo particle method ABSTRACTThe high-speed characteristics of InP/InGaAs HBTs with two different collector structures have been investigated using an ensemble Monte Carlo particle simulator. It has been demonstrated that vertical scaling of a standard HBT structure does not result in a substantial improvement of overall speed performance due to the increasing collector capacitance chargine time. As essential reduction of the collector transit delay time has been observed for HBT with nonuniform& doped (n--p+-n--n+) collector structure. The collector transit delay time is reduced due to the extension of the velociy overshoot @on in the collector. The parameters of HBT with proposed collector structure (n--p+-n--n+) have been optimized i n order to obtain the ultimate high-frequency performance under the high collector voltage. 0 1996 John Wiley & Sons, Inc.