InP/InGaAs double heterojunction bipolar transistors incorporating carbon-doped bases and superlattice graded base-collector junctions

High performance InP/InGaAs double heterojunction bipolar transistors (DHBTs) incorporating carbon-doped bases and graded base-collector junctions implemented using a short period superlattice were grown by gas source MBE (GSMBE). Base hole concentrations up to 106 x 1019cm-3 were obtained, using CCl4 as the dopant source. Transistors with 2 x 10 µm2 emitters achieved ft and fmax values up to 76 and 82 GHz, respectively. These devices demonstrate state of the art values of fmax. © 1993, The Institution of Electrical Engineers. All rights reserved.