Semiconductor device

A semiconductor device comprising:

• a semiconductor substrate;
• a transistor region in which a transistor is formed, the transistor including a first conductivity type base layer provided in a surface layer of the semiconductor substrate, a second conductivity type source layer selectively provided in a surface layer of the base layer, and a trench gate that extends so as to cross the source layer in plan view;
• a diode region that is disposed adjacent to the transistor region and in which a diode is formed;
• a boundary trench gate provided in a boundary portion between the transistor region and the diode region;
• and
• a carrier control region provided as the surface layer of the semiconductor substrate at a position closer to the boundary trench gate than the source layer located between the boundary trench gate and the trench gate, wherein
• a concentration of first conductivity type impurities contained in the carrier control region is higher than a concentration of the first conductivity type impurities contained in the source layer or a concentration of second conductivity type impurities contained in the carrier control region is lower than a concentration of the second conductivity type impurities contained in the source layer.