Patent ID: 10651298

Abstract:
The disclosure provides an HBT structure with bandgap graded hole barrier layer, comprising: a sub-collector layer, a collector layer, a hole barrier layer, a base layer, an emitter layer, an emitter cap layer, and an ohmic contact layer, all stacked sequentially on a substrate; with the hole barrier layer formed of at least one of AlGaAs, AlGaAsN, AlGaAsP, AlGaAsSb, and InAlGaAs, Aluminum composition being less than 22%, and In, N, P, and Sb compositions being respectively less than or equal to 10%; wherein bandgaps of the hole barrier layer at least comprise a gradually increasing bandgap from the base layer towards the collector layer and the largest bandgap of the hole barrier layer is greater than bandgaps of the base layer and the collector layer.