Patent ID: 10868122

Abstract:
During epitaxial growth of an n−-type drift layer having a uniform nitrogen concentration, vanadium is doped in addition to the nitrogen, whereby an n−-type lifetime reduced layer is selectively formed in the n−-type drift layer. The n−-type lifetime reduced layer is disposed at a depth that is more than 5 μm from a pn junction surface between a p-type anode layer and the n−-type drift layer in a direction toward a cathode side, and the n−-type lifetime reduced layer is disposed separated from the pn junction surface. Further, the n−-type lifetime reduced layer is disposed in a range from the pn junction surface to a depth that is ⅓ times a thickness of the n−-type drift layer. A vanadium concentration of the n−-type lifetime reduced layer is 1/100 to ⅕ of a nitrogen concentration of the n−-type lifetime reduced layer.