Patent ID: 6399993
Filing Date: 2002-06-04
Classification: H01L

Abstract:
A semiconductor device comprising:a substrate having a semiconductor layer at least in a surface region thereof; a collector layer of a first conductivity type, which is provided in the semiconductor layer; a base extended electrode, which is provided over the collector layer and is formed out of a conductor film with a first opening; a base undercoat insulating film, which is interposed between the substrate and the base extended electrode and has a second opening wider than the first opening; a base layer of a second conductivity type, which is provided on the semiconductor layer and includes a peripheral portion and a center portion, the peripheral portion being in contact with a lower edge of the base extend electrode around a periphery of the first opening, the center portion being located in an inner region of the second opening and deposited thicker than the peripheral portion; an emitter layer of the first conductivity type which is provided inside the first opening of the base extended electrode and is in contact with the upper surface of the center portion of the base layer; a bipolar transistor composed of an insulator film interposed between a side face of the first opening of the base extended electrode and the base and emitter layers; a gate insulating film formed out of an insulating film same as that of the undercoat insulating film and is provided on the semiconductor layer; and an MIS transistor formed out of a gate electrode provided on the gate insulating film.