SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

Disclosed is a semiconductor device wherein a p anode layer (2) is formed on the side of one main surface of an n- drift layer (1). On the side of the other main surface of the n- drift layer (1), an n+ cathode layer (3) having an impurity concentration higher than that of the n- drift layer (1) is formed. On the surface of the p anode layer (2), an anode electrode (4) is formed. On the surface of the n+ cathode layer (3), a cathode electrode (5) is formed. An n type broad buffer region (6) is formed inside of the n- drift layer (1), said broad buffer region having a net doping concentration higher than that of the bulk of a wafer and lower than that of the n+ cathode layer (3) and that of the p anode layer (2). The specific resistance (?0) of the n- drift layer (1) satisfies the inequalities of 0.12V0=?0=0.25V0, wherein V0 is the rated voltage. The total net doping concentration quantity in the broad buffer region (6) is 4.8×1011-1.0×1012 atoms/cm2.