DC, RF, AND NOISE CHARACTERISTICS OF CARBON-DOPED BASE INP INGAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/

The first successful demonstration of high-performance InP/InGaAs hete rojunction bipolar transistors utilizing a highly carbon-doped base is reported. The detailed device characteristics including dc, RF, and n oise performance have been investigated. For the first time base layer s free of hydrogen passivation have been obtained using chemical beam epitaxy. The HBT's showed almost ideal de characteristics; a gain inde pendent of collector current, a near unity ideality factor, a very sma ll offset-voltage, and a high breakdown voltage. Devices having two 1. 5 mu m x 15 mu m emitter fingers exhibited a maximum fT of 115 GBz and f(max) of 52 GHz. The device also exhibited a minimum noise figure of 3.6 dB and associated gain of 13.2 dB at a collector current level of 2 mA where a fT of 29 GHz and f(max) of 23 GHz were measured. The nea rly ideal dc characteristics, excellent speed performance, and RF nois e performance demonstrate the great potential of the carbon-doped base InP/InGaAs HBT's.