InP/InGaAs heterojunction bipolar transistors with regrown emitters

InP/InGaAs heterojunction bipolar transistors (HBTs) with regrown emitters for high-speed, low-power ICs have been fabricated with a newly developed structure. This is the first report of HBTs with regrown emitters as small as 2.5 /spl mu/m/spl times/2.5 /spl mu/m, small enough to be used in high-speed ICs, in this material system. Current gain of 24 was obtained with a 3.5 /spl mu/m/spl times/3.5 /spl mu/m emitter HBT. Short-range reliability of the regrown emitter HBTs was investigated for the first time. No degradation was observed in the current-voltage characteristics for 5000 sec under a collector current density as high as 1/spl times/10/sup 5/ A/cm/sup 2/.<>