Semiconductor device

A semiconductor device, comprising:

• an insulating layer;
• a first conductivity type semiconductor layer provided on the insulating layer;
• a base layer provided adjacent to the first conductivity type semiconductor layer and on the insulating layer;
• a second conductivity type semiconductor layer provided adjacent to the base layer on a side opposite to the first conductivity type semiconductor layer, and on the insulating layer;
• a first insulating film provided on a side wall of a plurality of first trenches extending from an edge part of the second conductivity type semiconductor layer toward the base layer side, but not reaching the base layer;
• a first electrode provided in the first trench via the first insulating film, and provided in contact with the edge part of the second conductivity type semiconductor layer;
• and
• a second electrode provided in contact with the first conductivity type semiconductor layer,
• the second conductivity type semiconductor layer including:
• a first second conductivity type region provided between the first trenches;
• and
• a second second conductivity type region provided between the first second conductivity type region and the base layer, and between an edge part on the base layer side of the first trench and the base layer, the second second conductivity type region being smaller in a quantity of second conductivity type impurities than the first second conductivity type region.

A semiconductor device, comprising a transistor cell and a diode cell connected in parallel between a first electrode and a second electrode, the first electrode provided on a first face side of a first conductivity type base layer, the second electrode provided on a second face side opposite to the first face,

• the transistor cell including:
• a second conductivity type base layer provided on the first conductivity type base layer;
• a first conductivity type semiconductor region provided on the second conductivity type base layer, and in contact with the first electrode;
• and
• a trench gate penetrating the second conductivity type base layer,
• the diode cell including:
• a second conductivity type semiconductor layer provided on the first conductivity type base layer;
• an insulating film provided on an inner wall of a plurality of trenches extending from a surface of the second conductivity type semiconductor layer toward the first conductivity type base layer side, but not reaching the first conductivity type base layer;
• and
• an buried electrode provided in the trench via the insulating film, and connected with the first electrode,
• the second conductivity type semiconductor layer including:
• a first second conductivity type region having a part provided between the trenches, and a part contacting the first electrode;
• and
• a second second conductivity type region provided between the first second conductivity type region and the first conductivity type base layer, and between a bottom part of the trench and the first conductivity type base layer, the second second conductivity type region being smaller in a quantity of second conductivity type impurities than the first second conductivity type region.