Semiconductor device to suppress leakage current

Abstract

Provided is a semiconductor device including: a buffer region having one or more doping concentration peaks having a higher doping concentration than a drift region; and a lifetime control portion provided at a position overlapping a shallowest concentration peak closest to a lower surface of a semiconductor substrate among the doping concentration peaks provided in the buffer region, and in which a carrier lifetime shows a local minimum value, in which the semiconductor substrate has a critical depth position at which an integrated value, which is obtained by integrating doping concentrations from an upper end of the drift region toward the lower surface, reaches a critical integrated concentration of the semiconductor substrate, and a depth position at which the carrier lifetime shows the local minimum value in the lifetime control portion is arranged closer to the lower surface than the critical depth position.