GAINP GAAS DOUBLE-HETEROJUNCTION BIPOLAR-TRANSISTOR WITH HIGH F(T), F(MAX), AND BREAKDOWN VOLTAGE/

We report on the dc and microwave performance of an MOCVD-grown carbon -doped GaInP/GaAs double heterojunction bipolar transistor (DHBT) with a thin highly doped n-type GaInP layer in the collector. The DHBT sho wed improved current-voltage characteristics at low collector-emitter bias compared with those of a DHBT without the heavily doped GaInP lay er, while maintaining a high breakdown voltage (BV(CEO) approximately 20 V). Small area, self-aligned emitter transistors with two 2 x 5 mum 2 emitter fingers were fabricated and exhibited f(T) and f(max) of 53 GHz and 75 GHz, respectively. These results indicate the promise of ca rbon-doped base GaInP/CaAs DHBT's for high-power microwave application s.