Semiconductor device and method for manufacturing semiconductor device

摘要

A p anode layer (2) is formed on one main surface of an n− drift layer (1). An n+ cathode layer (3) having an impurity concentration more than that of the n− drift layer (1) is formed on the other main surface of the n− drift layer (1). An anode electrode (4) is formed on the surface of the p anode layer (2). A cathode electrode (5) is formed on the surface of the n+ cathode layer (3). An n-type broad buffer region (6) that has a net doping concentration more than the bulk impurity concentration of a wafer and less than that of the n+ cathode layer (3) and the p anode layer (2) is formed in the n− drift layer (1). The resistivity ρ0 of the n− drift layer (1) satisfies 0.12V0≦ρ0≦0.25V0 with respect to a rated voltage V0. The total amount of the net doping concentration of the broad buffer region (6) is equal to or more than 4.8×1011 atoms/cm2 and equal to or less than 1.0×1012 atoms/cm2.

主权项

1. A semiconductor device comprising:
a first first-conductivity-type semiconductor layer; a second second-conductivity-type semiconductor layer that is provided on one main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer; a third first-conductivity-type semiconductor layer that is provided on the other main surface of the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer; and a first-conductivity-type broad buffer region that is provided in the first semiconductor layer and has an impurity concentration more than that of the first semiconductor layer and in which a local maximum value of an impurity concentration distribution is less than the impurity concentration of the second semiconductor layer and the third semiconductor layer, wherein the total amount of the 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, and wherein the resistivity ρ0 (Ωcm) of the first semiconductor layer satisfies 0.12V0≦ρ0≦0.25V0 with respect to a rated voltage V0 (V).