Patent ID: 7713812

Claim:
A method for manufacturing a semiconductor thin film, comprising: a first step of forming a first semiconductor thin film on a single-crystal substrate; a second step of selectively forming a mask film with a plurality of openings therein on the first semiconductor thin film; a fourth step of subjecting the first semiconductor thin film with the mask film formed thereon to a heat treatment in an oxidizing atmosphere to oxidize portions of the first semiconductor thin film that are exposed through the openings of the mask film and a vicinity thereof, thereby forming a plurality of oxidized regions in the first semiconductor thin film; a fifth step of removing the mask film to expose the first semiconductor thin film and then forming a second semiconductor thin film on the exposed first semiconductor thin film so as to cover the plurality of oxidized regions; a sixth step, after said fifth step, of separating the substrate from the first semiconductor thin film, wherein the sixth step includes a step of irradiating the substrate with irradiation light whose energy is smaller than a forbidden band width of a material of the substrate and is larger than a forbidden band width of a material of the first semiconductor thin film.