High-speed InP/InGaAs HBT with reduced intrinsic transit time

The high-speed characteristics of InP/InGaAs HBTs with two different collector structures have been investigated using an ensemble Monte Carlo particle simulator. A dramatic decrease of the collector delay time has been observed for HBTs with a non-uniformly doped (i-p/sup +/-i-n/sup +/) collector structure. The collector delay time is reduced due to the extension of the velocity overshoot region in the collector. The parameters of HBT with proposed collector structure (i-p/sup +/-i-n/sup +/) have been optimized in order to obtain the ultimate high-frequency performance under high collector voltage.