In0.52Al0.48As/In0.53Ga0.47As heterojunction bipolar transistor on GaAs by molecular beam epitaxy

Abstract
We report on the first In0.52Al0.48As/In0.53Ga0.47As heterojunction bipolar transistors grown on a GaAs substrate. In order to suppress the propagation of threading dislocations to the surface, a ten‐period AlAs/In0.52Al0.48As (20 Å/20 Å) strained‐layer superlattice was repeated twice with intervening undoped In0.52Al0.48As layers. The typical common emitter current gain in 50×50 μm2 emitter area devices was 50, with a maximum of 63, at a collector current density of 2×103 A/cm2.