Semiconductor device and method for manufacturing the same

A semiconductor device comprising:

• a semiconductor substrate having a main surface and a back surface;
• a drift region provided in the semiconductor substrate so as to be in contact with the main surface, the drift region having a first conductivity type;
• a body region selectively provided in the drift region, the body region having a second conductivity type different from the first conductivity type;
• first and second grooves passing through the body region, the first and second grooves extending in a first direction in plan view and disposed in a spaced relationship from each other in a second direction perpendicular to the first direction;
• a first semiconductor region formed in the body region, the first semiconductor region disposed between the first groove and the second groove and having the second conductivity type;
• a second semiconductor region formed in the body region, the second semiconductor region disposed between the first groove and the first semiconductor region and having the first conductivity type;
• a third semiconductor region formed in the body region, the third semiconductor region disposed between the second groove and the first semiconductor region and having the first conductivity type;
• a fourth semiconductor region formed in the drift region, the fourth semiconductor region disposed below the first and second grooves and having the second conductivity type;
• a first gate electrode formed in the first groove with a first gate insulating film interposed therebetween;
• a second gate electrode formed in the second groove with a second gate insulating film interposed therebetween;
• a first electrode formed on the main surface of the semiconductor substrate, the first electrode electrically connected to the first semiconductor region, the second semiconductor region, and the third semiconductor region;
• and
• a second electrode formed on the back surface of the semiconductor substrate, wherein
• the fourth semiconductor region continuously extends below the first groove and below the second groove in the first direction, and
• the fourth semiconductor region continuously extends below the first groove, the second semiconductor region, the first semiconductor region, the third semiconductor region, and the second groove in the second direction.