Semiconductor device

A semiconductor device comprising:

• a semiconductor substrate;
• a drift region of first conductivity type that is formed in the semiconductor substrate;
• an accumulation region of first conductivity type that is formed above the drift region and has a higher concentration than a concentration of the drift region;
• a base region of second conductivity type that is formed above the accumulation region;
• and
• a gate trench portion that is formed extending from an upper surface of the semiconductor substrate to the drift region, passing through the base region and the accumulation region, wherein
• a maximum value of a doping concentration of the accumulation region is greater than a maximum value of a doping concentration of the base region,
• a doping concentration distribution of the accumulation region in a depth direction has at least one peak, and a doping concentration distribution of the base region in the depth direction has at least one peak, and
• an integrated concentration that is obtained by integrating the doping concentration of the accumulation region in the depth direction of the semiconductor substrate is less than an integrated concentration that is obtained by integrating the doping concentration of the base region in the depth direction of the semiconductor substrate.