Patent ID: 6881261

Claim:
A method for fabricating a semiconductor device having a semiconductor layer formed by epitaxial growth from a single-crystal substrate, the method comprising the steps of: (a) forming a multilayer film having at least a first semiconductor layer composed of a group III-V compound doped with a p-type impurity and containing nitrogen and an n-type second semiconductor layer composed of a group III-V compound doped with an n-type impurity and containing nitrogen such that the single-crystal substrate is covered with the multilayer film; and (b) irradiating the first semiconductor layer with a light beam to activate the p-type impurity in the first semiconductor layer, wherein the step (a) includes forming the first semiconductor layer below the second semiconductor layer and the step (b) includes irradiating the first semiconductor layer with the light beam through a back surface of the single-crystal substrate, wherein the step (b) includes performing a first-stage treatment for activating the p-type impurity in the first semiconductor layer and performing a second-stage treatment for varying a power density or energy of the light beam to separate the first semiconductor layer and the single-crystal substrate from each other.