Semiconductor device

A semiconductor device, comprising:

• a semiconductor layer;
• a first base region of a first conductivity type selectively provided on the surface of the semiconductor layer;
• a first source region of a second conductivity type selectively provided on the surface of the first base region;
• a second base region of the first conductivity type selectively provided on the surface of the semiconductor layer spaced from the first base region;
• a second source region of a second conductivity type selectively provided on the surface of the second base region;
• a back gate region of the first conductivity type provided on the surface of the second base region adjacent to the second source region;
• a drift region of the second conductivity type sandwiched between the first base region and the second base region and selectively provided on the surface of the semiconductor layer;
• a drain region of the second conductivity type selectively provided on a surface of the drift region;
• a first insulating region provided to an interior from the surface of the drift region and facing the first base region via a portion of the drift region disposed;
• a second insulating region provided to the interior from the surface of the drift region and facing the second base region via a portion of the drift region disposed, the drain region being sandwiched between the first insulating region and the second insulating region;
• a first gate oxide film provided on the surface of the first base region;
• a second gate oxide film provided on the surface of the second base region;
• a first gate electrode provided on the first base region and the drift region via the first gate oxide film;
• a second gate electrode provided on the second base region and the drift region via the second gate oxide film;
• a first main electrode connected to the first source region, the second source region, and the back gate region;
• and
• a second main electrode connected to the drain region,
• a distance between the first base region and the first insulating region being not more than 1.8 μm, the first base region facing the first insulating region via a portion of the drift region and a distance between the second base region and the second insulating region being not more than 1.8 μm, the second base region facing the second insulating region via a portion of the drift region, and
• a distance of the first insulating region between the drift region adjacent to the first base region and the drain region is longer than a distance of the second insulating region between the drift region adjacent to the second base region and the drain region.