Molecular beam epitaxial growth and characterization of InP/GaAsSb/InP double heterojunction bipolar transistors

Abstract

InP/GaAsSb/InP double heterojunction bipolar transistor structures were grown in a solid-source molecular beam epitaxy system. Carbon or Be was used for the p-type doping of GaAs 0.51Sb 0.49. Hole concentrations in excess 2×10 20 cm −3 were obtained in carbon doped GaAs 0.51Sb 0.49 films. InP/GaAsSb/InP double heterojunction bipolar transistors were fabricated as wet-etched triple mesa structures. Common-emitter current gain, β, >80 was measured for large area devices with 20×20 μm 2 emitter geometry, and a base doping of 1×10 19 cm −3. BV CEO>6 V was measured for devices incorporating a 2000 Å thick InP collector. The gain of the transistor decreased to 20 as the base doping level was increased to 5×10 19 cm −3.