SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

A provided method of manufacturing a semiconductor device includes formation of an interlayer insulating. The interlayer insulating film includes first and second insulating layers. The first insulating layer covers an upper surface of each of the gate electrodes. The second insulating layer is located on the first insulating layer. A contact hole is provided in the interlayer insulating film at a position between the trenches. Then the interlayer insulating film is heated at a temperature lower than the softening temperature of the first insulating layer and higher than the softening temperature of the second insulating layer so as to make a surface of the second insulating layer into a curved surface so that surfaces of end portions of the second insulating layer are sloping from the corresponding contact holes so as to be displaced upward toward a center of the corresponding trench.