Abstract: According to one embodiment, a first distance is a distance between both ends of the first insulating film in a direction connecting the fourth semiconductor layer and the sixth semiconductor layer. The first distance in the first region is longer than the first distance in the second region. A second distance is a distance between an edge of the second insulating film on an inner peripheral side of the second semiconductor layer and an edge of the third semiconductor layer on an outer peripheral side of the second semiconductor layer. The second distance in the first region is shorter than the second distance in the second region.

Abstract: According to one embodiment, a first distance is a distance between both ends of the first insulating film in a direction connecting the fourth semiconductor layer and the sixth semiconductor layer. The first distance in the first region is longer than the first distance in the second region. A second distance is a distance between an edge of the second insulating film on an inner peripheral side of the second semiconductor layer and an edge of the third semiconductor layer on an outer peripheral side of the second semiconductor layer. The second distance in the first region is shorter than the second distance in the second region.

Abstract: A first semiconductor layer extends from the element region to the element-termination region, and functions as a drain of the MOS transistor. A second semiconductor layer extends, below the first semiconductor layer, from the element region to the element-termination region. A third semiconductor layer extends from the element region to the element-termination region, and is in contact with the second semiconductor layer to function as a drift layer of the MOS transistor. A distance between a boundary between the first semiconductor layer and the field oxide film, and the end portion of the third semiconductor layer on the fifth semiconductor layer side in the element region is smaller than that between a boundary between the first semiconductor layer and the field oxide layer and an end portion of the third semiconductor layer on the fifth semiconductor layer side in the element-termination region.

Abstract: A first semiconductor layer extends from the element region to the element-termination region, and functions as a drain of the MOS transistor. A second semiconductor layer extends, below the first semiconductor layer, from the element region to the element-termination region. A third semiconductor layer extends from the element region to the element-termination region, and is in contact with the second semiconductor layer to function as a drift layer of the MOS transistor. A distance between a boundary between the first semiconductor layer and the field oxide film, and the end portion of the third semiconductor layer on the fifth semiconductor layer side in the element region is smaller than that between a boundary between the first semiconductor layer and the field oxide layer and an end portion of the third semiconductor layer on the fifth semiconductor layer side in the element-termination region.

Abstract: 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.

Abstract: A first semiconductor layer extends from the element region to the element-termination region, and functions as a drain of the MOS transistor. A second semiconductor layer extends, below the first semiconductor layer, from the element region to the element-termination region. A third semiconductor layer extends from the element region to the element-termination region, and is in contact with the second semiconductor layer to function as a drift layer of the MOS transistor. A distance between a boundary between the first semiconductor layer and the field oxide film, and the end portion of the third semiconductor layer on the fifth semiconductor layer side in the element region is smaller than that between a boundary between the first semiconductor layer and the field oxide layer and an end portion of the third semiconductor layer on the fifth semiconductor layer side in the element-termination region.

Abstract: 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.