CPC H01L 29/7806 (2013.01) [H01L 21/049 (2013.01); H01L 29/0696 (2013.01); H01L 29/1608 (2013.01); H01L 29/66068 (2013.01)] | 20 Claims |
1. A semiconductor device comprising:
a semiconductor layer having a first main surface on one side and a second main surface on the other side;
a unit cell including a diode region of a first conductivity type formed in a surface layer portion of the first main surface, a well region of a second conductivity type formed in the surface layer portion of the first main surface along a peripheral edge of the diode region, and a first conductivity type region formed in a surface layer portion of the well region;
a gate electrode layer that faces the well region and the first conductivity type region across a gate insulating layer, and that has a side wall located on the first conductivity type region;
an insulating film that covers over the gate electrode layer; and
a first main surface electrode electrically connected to the diode region and the first conductivity type region on the first main surface, the first main surface electrode forming a Schottky junction with the diode region,
wherein the first main surface of the semiconductor layer includes a recessed portion that is formed in a region located at a side of the gate electrode layer such as to be recessed toward the second main surface and that exposes at least a part of the first conductivity type region,
the insulating film has a first portion that covers the recessed portion and extends along the recessed portion from the side wall of the gate electrode layer and a second portion that covers the side wall of the gate electrode layer and extends along the side wall of the gate electrode layer, and
a thickness of the first portion of the insulating film perpendicular to an extending direction of the first portion of the insulating film is greater than a thickness of the second portion of the insulating film perpendicular to an extending direction of the second portion of the insulating film.
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