Method of fabricating semiconductor device

摘要

Disclosed is a method of fabricating a semiconductor device in which at least an LDD type insulated-gate field effect transistor and a bipolar transistor are formed on a common base substrate. An insulating layer for forming side walls of an LDD type insulated-gate field effect transistor is formed by a stack of first and second insulating films. An opening is formed in the lower first insulating film at a position in a bipolar transistor forming area, and a single crystal semiconductor layer is formed on a base substrate through the opening. With this configuration, the fabrication steps can be simplified and the reliability of the semiconductor device can be enhanced.