ULTRAHIGH F(T) AND F(MAX) NEW SELF-ALIGNMENT INP/INGAAS HBTS WITH A HIGHLY BE-DOPED BASE LAYER GROWN BY ALE/MOCVD

We report on a new self-alignment (S.A.) process and microwave performance of ALE/MOCVD grown InP/InGaAs heterojunction bipolar transistors (HBT's) with a base doping concentration of 1 x 10(20) cm(-3). We obtained f(T) of 161 GHz and f(max) of 167 GHz with a 2 x 10 mu m emitter. These high values indicate the best performance of InP/InGaAs HBT's ever reported, in so far as we know. These values were attained by reducing the base resistance using ALE/MOCVD and base-collector capacitance using a new S.A. process. These results indicate the great potential of these devices for ultrahigh-speed application.