Pressed-contact type semiconductor device

A pressed-contact type semiconductor device comprising:

• a first conductivity type of semiconductor substrate;
• a first diffusion layer formed by diffusing a second conductivity type of impurities on a first side of the semiconductor substrate;
• a fourth diffusion layer formed by diffusing a first conductivity type of impurities on the first side of the semiconductor substrate so as to be shallower than the first diffusion layer;
• a gate electrode provided on the first side of the semiconductor substrate so as to be in contact with the first diffusion layer;
• a first electrode provided on the first side of the semiconductor substrate so as to be in contact with the fourth diffusion layer;
• a second diffusion layer locally formed by diffusing the second conductivity type of impurities on a second side of the semiconductor substrate so as to be exposed on a lateral side of the substrate;
• a third diffusion layer locally formed by diffusing the second conductivity type of impurities on the second side of the semiconductor substrate so as not to be exposed on the lateral side of the substrate;
• and
• a second electrode provided on the second side of the semiconductor substrate so as to be in contact with the third diffusion layer;
• wherein a plurality of lifetime control regions each having a lifetime shorter than that of the semiconductor substrate are formed inside the semiconductor substrate so as to be substantially parallel to the substrate surface, and a first lifetime control region which is closest to the second and third diffusion layers has a lifetime shorter than that of a second lifetime control region which is second closest to the second and third diffusion layers.