Patent ID: 6861340

Claim:
A method of decreasing the resistance of and activating a nitride compound semiconductor layer doped with a p-type impurity, said method comprising heating a nitride compound semiconductor layer doped with a p-type impurity, at a temperature that is at least 200° C. but less than 400° C. for at least 200 minutes, in one atmosphere selected from; (A) aerial atmosphere, (B) an atmosphere supplied with an oxygen gas and a hydrogen gas, (C) an atmosphere supplied with an oxygen gas and steam, (D) an atmosphere supplied with an oxygen gas, a hydrogen gas and steam, (E) an inert gas atmosphere containing steam, or (F) a reduced-pressure atmosphere containing steam and having a pressure lower than atmospheric pressure, and forming on the surface of said nitride compound semiconductor layer a hydrogen-permeable film, said hydrogen-permeable film having a thickness to prevent the dissociation of nitrogen atoms from the nitride compound semiconductor layer by the heat treatments, wherein dissociation of hydrogen in said nitride compound semiconductor layer is promoted and wherein said dissociation decreases the resistance of and activates said nitride compound semiconductor layer.