SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

A p anode layer is formed on one main surface of an n− drift layer. N+ cathode layer having an impurity concentration more than that of the n− drift layer is formed on the other main surface. An anode electrode is formed on the surface of the p anode layer. A cathode electrode is formed on the surface of the n+ cathode layer. N-type broad buffer region having a net doping concentration more than the bulk impurity concentration of a wafer and less than the n+ cathode layer and p anode layer is formed in the n− drift layer. Resistivity ρ0 of the n− drift layer satisfies 0.12V0≦ρ0≦0.25V0 with respect to rated voltage V0. Total amount of net doping concentration of the broad buffer region is equal to or more than 4.8×1011 atoms/cm2 and equal to or less than 1.0×1012 atoms/cm2.