Patent ID: 7303986

Claim:
A method of manufacturing a semiconductor device comprising the steps of: (a) forming MISFETs in a semiconductor substrate; (b) forming a first insulating film over said MISFETs; (c) forming a first wiring and a second wiring over said first insulating film; (d) after said step (c), forming a second insulating film connected to said first and second wirings; (e) after said step (d), forming a third insulating film over said second insulating film; (f) after said step (e), cleaning a surface of said third insulating film; (g) after said step (f), forming a plurality of holes in said second and third insulating films; and (h) after said step (g), forming a third wiring over said third insulating film such that said third wiring is connected to said first and second wirings via said holes, wherein before said step (h), said first wiring is in a floating state and said second wiring is connected to said semiconductor substrate, wherein a silicon content of said second insulating film is higher than that of said third insulating film, wherein said step (c) comprises the steps of: (c1) forming a first titanium nitride film over said first insulating film; (c2) forming an aluminium film or aluminium alloy film over said first titanium nitride film; (c3) forming a second titanium nitride film over said aluminium or aluminium alloy film; and (c4) patterning said first titanium nitride film, said aluminium or aluminium alloy film and said second titanium nitride film, and wherein, in said step (d), said second insulating film is connected to said aluminium film or aluminium alloy film of said first and second wirings.