Bipolar transistor and semiconductor integrated circuit device

摘要

A bipolar transistor has a semiconductor region of a first conductivity type. A collector region of the first conductivity type and a base region of a second conductivity type are disposed within the semiconductor region. An emitter region of the first conductivity type and a base electrode region of the second conductivity type are disposed within a surface of the base region in self-alignment arrangement. At least one polycrystalline silicon layer is disposed on the entire surface of the base region except for portions of the surface of the base region overlying the emitter region and the base electrode region.