A f/sub T/=175 GHz carbon-doped base InP/InGaAs HBT

We report the microwave characteristics of an InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistor (HBT) utilizing a highly carbon-doped base grown by chemical beam epitaxy (CBE). The HBT having two 1.5/spl times/10 /spl mu/m/sup 2/ emitter fingers exhibited f/sub T/ and f/sub max(MAG)/ of 175 GHz and 70 GHz, respectively, at I/sub C/=40 mA and V/sub CE/=1.5 V. To our knowledge, the f/sub T/ of this device is the highest of any type of bipolar transistors yet reported. The results indicate the great potential of carbon-doped base InP/InGaAs HBTs for high-speed applications.<
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