Compound semiconductor device

摘要

A compound semiconductor device having a mesa type heterojunction bipolar transistor comprises a collector layer of first conductivity type having a collector breakdown voltage of a predetermined magnitude, a base layer of second conductivity type formed on the collector layer, an emitter layer of first conductivity type formed on the base layer, and a subcollector layer of first conductivity formed in a region remote laterally from an edge of the base layer to be connected to the collector layer.