Patent ID: 7741228

Claim:
A method for fabricating a semiconductor device comprising the steps of: (a) forming a first insulating film on a substrate; (b) forming a wiring groove in the first insulating film; (c) forming a wire inside the wiring groove; (d) forming a protection film on the first insulating film and on the wire; (e) forming a hard mask film on the protection film; (f) patterning the hard mask film; (g) partially removing the protection film and the first insulating film using the patterned hard mask film to form an air gap groove; and (h) forming a second insulating film to close an upper portion of the air gap groove for forming an air gap, wherein: the method further includes, between the steps (g) and (h), step of (i) removing the hard mask film, and the step (i) includes performing wet etching to remove the hard mask film, and removing part of the first insulating film located near the air gap groove to extend the air gap groove.