Ultra-high-speed InP/InGaAs heterojunction bipolar transistors

We report on the microwave performance of InP/In/sub 0.53/Ga/sub 0.47/As heterojunction bipolar transistors (HBT's) utilizing a carbon-doped base grown by chemical beam epitaxy (CBE). The f/sub T/ and f/sub max/ of the HBT having two 1.5/spl times/10 /spl mu/m/sup 2/ emitter fingers were 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. These results indicate the great potential of carbon-doped base InP/InGaAs HBT's for high-speed applications. >