METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE

According to one embodiment, a method is disclosed for manufacturing a semiconductor device. The method can include simultaneously forming a first field insulating film and at least one second field insulating film on a front face side of a semiconductor layer. The at least one second field insulating film is separated from the first field insulating film and thinner than the first field insulating film. The method can include forming a drift region of a first conductivity type in a region of the semiconductor layer including the first field insulating film and the second field insulating film. The method can include forming a drain region of the first conductivity type in the front face of the semiconductor layer on a side of the first field insulating film. In addition, the method can include forming a source region of the first conductivity type in the front face of the semiconductor layer on a side of the second field insulating film.