Patent ID: 7405121

Claim:
A method of manufacturing a semiconductor device comprising steps of: (a) forming an interlayer insulating film over a semiconductor substrate; (b) forming a via hole through the interlayer insulating film and filling the via hole with a conductive plug; (c) forming an oxygen barrier film over an upper surface of the conductive plug and over an upper surface of the interlayer insulating film; (d) depositing a lower electrode layer on the oxygen barrier film; (e) executing heat treatment to form an intermediate film at an interface between the oxygen barrier film and the lower electrode layer, the intermediate film being made of alloy which contains at least one constituent element of the oxygen barrier film and at least one constituent element of the lower electrode layer; (f) sequentially forming a dielectric layer and an upper electrode layer on the lower electrode layer; and (g) patterning each of layers between the oxygen barrier film and the upper electrode layer to leave the oxygen barrier film in an area where the conductive plug is disposed.