High fmax carbon-doped base InP/InGaAs heterojunction bipolar transistors grown by MOCVD
The authors report excellent microwave characteristics of C-doped base InP/InGaAs heterojunction bipolar transistors (HBTs) grown by metalorganic chemical vapour deposition (MOCVD). A combination of a low resistance base layer (2.5 × 1019 cm-3, 700 Å) and a very narrow emitter mesa structure (0.5 × 4.7 µm2) enabled us to achieve a record maximum oscillation frequency (fmax) of 170 GHz at JC = 1.7 × 105 A/cm2 for C-doped base InP/InGaAs HBTs.