Compound semiconductor bipolar device with side wall contact

摘要

A high-speed compound semiconductor device includes semiconductor layers of a group III-V alloy laminated in a vertical direction. The device uses a base electrode that contacts side walls and covers a step portion of a base layer. The device includes an intermediate layer positioned between and comprising a different semiconductor material than that of base and collector layers. The intermediate layer has a different etching rate than those of the base and collector layers. The intermediate layer can be a collector-side barrier layer formed between the collector and base layers in a HET or RHET device. The device of the present invention has reduced capacitance between the base and collector layers and reduced base layer resistance.