Semiconductor device and method of manufacturing semiconductor device

A semiconductor device comprising:

• a semiconductor substrate with a first main surface and a second main surface;
• a drift layer of a first conductivity type formed in the semiconductor substrate;
• a first impurity diffusion layer of a second conductivity type formed on the drift layer to be closer to the first main surface;
• and
• a buffer layer of the first conductivity type formed on the drift layer to be closer to the second main surface and higher in peak impurity concentration than the drift layer,
• the drift layer having a first trap of an energy level lower than energy at a bottom of a conduction band by 0.234 eV, a second trap of an energy level lower than the energy at the bottom of the conduction band by 0.349 eV, and a third trap of an energy level lower than the energy at the bottom of the conduction band by 0.470 eV,
• the second trap having trap density of equal to or greater than 2.0×1011 cm−3.