Semiconductor device and power amplifier using the same

摘要

A semiconductor device comprising a bipolar transistor having an emitter layer consisting of a semiconductor containing indium, and a protective insulating film containing silicon and oxygen which is formed on the surface of the guard ring of the emitter layer, wherein the protective insulating film has a density of oxygen of less than 7x10<22 >cm<-3>. This semiconductor device prevents performance deterioration and ensures high performance in a power amplifier.