Semiconductor device and manufacturing method thereof

A semiconductor device comprising:

• a first electrode;
• a second electrode;
• a first semiconductor region of a first conductivity type between the first electrode and the second electrode;
• a plurality of second semiconductor regions of a second conductivity type selectively provided between the first semiconductor region and the second electrode;
• a third semiconductor region of the first conductivity type provided between the second semiconductor regions and the second electrode;
• an insulating film provided on the first semiconductor region in a location between adjacent second semiconductor regions, the second semiconductor regions, and the third semiconductor region;
• and
• a third electrode located over the insulating film, wherein a portion of the insulating film and the third electrode extend inwardly of the second semiconductor regions,
• wherein the corners of the third electrode are inset into end portions of the second semiconductor region, such that a portion of the second semiconductor region extends between the inset portion of the third electrode and the first semiconductor region.