SEMICONDUCTOR DEVICE HAVING A HETEROJUNCTION BIOPOLAR TRANSISTOR AND A FIELD EFFECT TRANSISTOR

摘要

A semiconductor device with a heterojunction bipolar transistor (HBT) and a field effect transistor (FET) formed over the same substrate; providing improved HBT characteristics and a lowered HBT collector resistance and also satisfactory etching of the FET gate recess, along with low ON-resistance in the FET. The sub-collector layer of a heterojunction bipolar transistor (HBT) is a laminated structure of multiple semiconductor layers, and moreover with a collector electrode formed on a section projecting out from one collector layer. In two of the FET, at least one semiconductor layer on the semiconductor substrate side of the semiconductor layers forming the sub-collector layer of the HBT also serves as at least a portion of a capacitor layer. The total film thickness of the HBT sub-collector layer is 500 nm or more; and the total film thickness of the FET capacitor layer is between 50 nm and 300 nm.