Method of manufacturing a semiconductor device having self-aligned

Abstract

A method of forming self-aligned contact holes of a semiconductor device presents bridging from occurring between contacts formed in the holes. First, gate electrode structures are formed on a semiconductor substrate. Next, an interlayer insulating film is formed over the gate electrode structures. The interlayer insulating film is formed by forming a first oxide layer of a reflowable material over the semiconductor substrate and gate electrode structures, planarization etching the first oxide layer until the upper portions of the gate electrode structures are uncovered, and then forming a second oxide layer on the planarized upper surface of the first oxide layer. The second oxide layer is selected to have a wet etch rate that is lower than that of the first oxide layer. Then, the insulating film is etched to form a contact hole between gate electrode structures. Finally, a self-aligned contact electrically connected with the semiconductor substrate is formed by filling the contact hole with conductive material.