Semiconductor device

Abstract

A method for fabricating a semiconductor device in which diffusion regions are formed in a silicon substrate with use of a gate electrode parts having side walls as a mask, including the steps of: (a) forming a gate electrode on a silicon substrate with a gate oxide interposed therebetween; (b) depositing an insulation film to entirely cover the substrate and the gate electrode, followed by depositing a polysilicon or amorphous silicon layer on the insulation film; (c) forming side walls of SiO.sub.2 on lateral sides of the gate electrode covered with the insulation film and the polysilicon or amorphous silicon layer, followed by ion implantation; and (d) subjecting the resulting substrate to a heat treatment at a medium temperature after removal of the side walls, followed by stacking an interlayer insulator after removal of the polysilicon or amorphous silicon layer, and subjecting the resultant to a heat treatment at a high temperature.

Dependencies are inferred from the claim text.