Electron transport in thin-base InP/InGaAs HBTs

A computational and experimental study of electron transport in p/sup +/-InGaAs is described. Monte Carlo simulations are in good accord with recent experiments in InP/InGaAs HBTs (heterojunction bipolar transistors), but to further test the microscopic model, zero-field, time-of-flight studies were also conducted. The Monte Carlo simulations reveal that the base transit time is strongly influenced by small amounts of carrier scattering. The base transit time varies approximately as W/sup 2//sub B/ even when most of the electrons cross the base ballistically. Clear ballistic behavior is observed only when the base width is a small fraction of the mean free path.