Method of manufacturing a semiconductor memory using dummy source/drain

Abstract

A method of manufacturing a semiconductor memory includes the steps of, on a semiconductor substrate having underlayer wiring which is composed of a plurality of gate portions provided with side walls and a diffused region between the gate regions, i) forming a layer insulating film which is smaller in thickness in the diffused region than the side walls of each of the gate regions and which is made of a material etched more easily than the material of the semiconductor substrate; ii) depositing a conductive layer of a material etched more easily than the layer insulating film, over the entire surface of the layer insulating film; iii) removing the conductive layer simply except a portion where a contact hole is to be formed in the diffused region, by etching with a pattern film for forming the contact hole; iv) depositing an insulating film and a pattern film for forming the contact hole over the entire surface again; and v) removing the insulating film, the remaining conductive layer and the layer insulating film by etching one after another to form the contact hole extending to the diffused region in self-alignment.