Semiconductor device and method of manufacturing the same

Abstract

Since a field effect MOS transistor can be formed with a reduced number of manufacturing processes, a semiconductor integrated circuit device can be materialized at a low cost. A semiconductor device has a structure in which a gate electrode is provided in the vicinity of the surface of a semiconductor substrate through a gate insulating film, a second conductive type heavily doped impurity region is provided in a region adjacent to a part of the gate electrode through a part of the gate insulating film and a part of a thick oxide film, another second conductive type heavily doped impurity region is provided in a region adjacent to an opposite part of the gate electrode opposing the part of the gate electrode through the part of the gate insulating film and a part of another thick oxide film, and a first conductive type heavily doped impurity region for device isolation is provided so as to surround the gate electrode and the second conductive type heavily doped impurity regions.