Method of manufacturing semiconductor device that uses both a normal photomask and a phase shift mask for defining interconnect patterns

According to one embodiment of the present invention, a method of manufacturing a semiconductor device includes below steps. A step of preparing a phase shift mask and a normal photomask. A step of stacking a first wiring layer on a semiconductor substrate, and further stacking, on the first wiring layer, a second wiring layer. The second wiring layer includes a second wiring and third wiring. A step of stacking an interlayer insulating film on the second wiring layer. A step of forming, in the interlayer insulating film, a first opening in which the second wiring is exposed, and a second opening in which the third wiring is exposed by photolithography using the normal photomask. A step of burying a metal in the first opening and the second opening. A step of providing a pad to be overlaid on the first and second openings.