Patent ID: 8238391

Claim:
A p-type group III nitride semiconductor, characterized in that an acceptor impurity atom in a concentration of 5×10 18 to 1×10 20 cm −3 is doped in a group III nitride semiconductor having a composition expressed by Al X Ga Y In Z N, where each of X, Y and Z indicates a rational number satisfying 1.0>X≧0.5, 0.5≧Y≧0.0 and 0.5≧Z≧0.0, and satisfies a relationship of X+Y+Z=1.0, a proportion of a hole concentration at 30° C. to an acceptor impurity atom concentration is 0.001 or more, activation energy of said acceptor impurity atom in said p-type group III nitride semiconductor in a T1 region (30 to 230° C.) is smaller than activation energy thereof in a T2 region (230° C. to 525° C.), and the activation energy of said acceptor impurity atom in said p-type group III nitride semiconductor in said T1 region is 200 meV or less.