Semiconductor device and method for manufacturing the same

摘要

A semiconductor device in which a lateral bipolar transistor and a CMOS transistor are hybrid-integrated, and the lateral bipolar transistor includes an open region opened in a device isolating oxide film surrounding an active region; a polysilicon film formed on the open region; and a protective film covering at least a part of a peripheral surface of the active region exposed by opening the open region in the device isolating oxide film, wherein the polysilicon film has such a thickness as to expose the active region out of the polysilicon film, and the protective film is a film for preventing the active region from being etched when the polysilicon film is etched to the thickness.