Semiconductor device

A semiconductor device, comprising:

• a second conductive first semiconductor region disposed selectively on a surface layer of a first conductive semiconductor substrate;
• a first conductive second semiconductor region disposed selectively inside the first semiconductor region;
• a first conductive third semiconductor region disposed selectively so as to be separated from the second semiconductor region inside the first semiconductor region;
• a first conductive fourth semiconductor region that is disposed so as to cover the third semiconductor region inside the first semiconductor region and extends over a part sandwiched between the second semiconductor region and the third semiconductor region to be in contact with the second semiconductor region in the first semiconductor region, wherein the first conductive fourth semiconductor region has lower impurity concentration than each of the second semiconductor region and the third semiconductor region;
• a local dielectric film disposed selectively on the surface layer of the part sandwiched between the second semiconductor region and the third semiconductor region in the fourth semiconductor region;
• a gate electrode disposed through a gate dielectric film on a surface of a part sandwiched between the local dielectric film and the second semiconductor region in the fourth semiconductor region;
• a first conductive fifth semiconductor region disposed at a part located toward the second semiconductor region through the local dielectric film in the fourth semiconductor region to be in contact with the second semiconductor region, wherein the first conductive fifth semiconductor region has lower impurity concentration than the fourth semiconductor region;
• a first electrode being in contact with the second semiconductor region;
• and
• a second electrode being in contact with the third semiconductor region.