Semiconductor device having etching stopper layer formed by oxidation and method of fabricating the same

摘要

A process for fabricating a semiconductor device using an etching stopper film which does not increase the number of photo-etching steps and does not cause a deterioration in device characteristics comprises the steps of: forming an impurity region at the surface of a semiconductor substrate; forming a first insulating layer on the semiconductor substrate; forming a first hole in the first insulating layer and thereby exposing the impurity region; forming a first metal layer on the first insulating layer and the inner surface of the first hole; forming a second metal layer on the region of the first metal layer formed on the inner surface of the first hole and filling the first hole with the second metal layer; oxidizing the first metal layer with the second metal layer as a mask; forming a second insulating layer on the first metal layer and the second metal layer; forming a second hole in the second insulating layer exposing the second metal layer by etching the second insulating layer with the first metal layer and the second metal layer as etching stoppers; and filling the second hole with a metal and thereby forming a third metal layer.