Manufacturing method of semiconductor device comprising bicmos transistor

Abstract

A method of manufacturing a semiconductor device including selectively forming an element-isolating insulating layer on a surface of a semiconductor substrate to define active regions; forming a first insulating layer and removing respective portions thereof on surfaces of a second conductive type active region and a first active region of a first conductive type; oxidizing to form a gate oxide layer; forming and patterning a conductive layer to form a gate electrodes of MOS transistors and a base-extracting electrode of a bipolar transistor; forming an opening, in the base-extracting electrode, and a side wall insulating layer on an inner wall of the opening; removing first and second portions of the insulating layer to form an overhung portion; epitaxially growing a second conductive type semiconductor layer using the base-extracting electrode and active region of the first conductive type as a seed crystal; and selectively forming a first conductive type semiconductor layer that is to become an emitter that does not contact the base-extracting electrode.