InP/GaAsSb/InP double HBTs: A new alternative for InP-based DHB

We report on the physical operation and performance of MOCVD-grown abrupt h eterojunction InP/GaAs0.51Sb0.49/ InP double heterojunction bipolar transis tors (DHBTs). In particular, the effect of the InP collector thickness on t he breakdown voltage and on the current gain cutoff frequency is assessed a nd a f(T) of 106 GHz is reported for a DHBT with a 400 A base and a 2000 An gstrom InP collector with a BVCEO of 8 V. We show that InP/GaAsSb/InP DHBTs are characterized by a weak variation m of fT as a function of temperature . Finally, we also demonstrate that high maximum oscillation frequencies f( MAX) > f(T) can be achieved in scaled high-speed InP/GaAsSb/InP DHBTs, and provide estimates of the maximum cutoff frequencies achievable for this eme rgent but promising material system. Recent results on improved structures validate our performance predictions with cutoff frequencies well beyond 20 0 GHz.