Patent ID: 6927107

Claim:
A method of producing a semiconductor device comprising: an element adding step of adding to an amorphous silicon film a catalyst element or elements serving to promote crystallization of the amorphous silicon film, said amorphous silicon film being formed on a substrate having an insulating surface; a first crystalization step of subjecting the amorphous silicon film to heat treatment to cause crystal growth of the amorphous silicon film, said crystal growth being stopped in a state that minute amorphous regions remain, a second crystallization step of irradiating the amorphous silicon film, of which the crystal growth has been stopped in a state that minute amorphous regions remain, with a strong light to cause further crystallization; and wherein in the second crystallization step, the irradiation of the strong light is performed at an intensity which allows the amorphous regions to be crystallized reflecting the crystallinity of the crystallized regions, but which does not allow an original crystallinity of the crystallized regions to be lost.