HIGH-SPEED, LOW-NOISE INGAP/GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS

We have demonstrated self-aligned InGaP/GaAs heterojunction bipolar transistors (HBT's) with excellent de, microwave, and noise performance, A 3 x 10 mu m(2) emitter finger device achieved a cutoff Frequency of f(T) = 66 GHz and a maximum frequency of oscillation of f(max) = 109 GHz, A minimum noise figure of 1.12 dB and an associated gain of 11 dB were measured at 4 GHz. These results are the highest combined f(T) + f(max) and the lowest noise figure reported for an InGaP/GaAs HBT and are attributed to material quality and the use of self-aligned base contacts. These data clearly demonstrate the viability of InGaP/GaAs HBT's for high-speed, low-noise circuit applications.