Patent ID: 7067404

Claim:
A method for producing a substrate sheet for thin film semiconductor devices comprising steps of; (a) depositing a layer of non-single-crystalline semiconductor on a base layer of insulation materials, (b) forming oxygen implanted areas in the layer of non-single-crystalline by implanting oxygen ion into the layer, and (c) irradiating the layer of non-single-crystalline semiconductor with energy beam by one step irradiation, thereby changing the layer of non-single-crystalline semiconductor so that the oxygen implanted areas are converted to insulating oxidized films and other areas are converted to films of semiconductor crystal grains in which a plurality of single-crystal grains are arranged in a two-dimensionally regulated mode, and the irradiation of energy beam is carried out so that an area to which an irradiation intensity of maximum value, which is sufficient to melt the non-single-crystalline semiconductor, is given and an area to which an irradiation intensity of minimum value, which does not cause the melt of the non-single-crystalline semiconductor, is given are arranged in a two-dimensionally regulated mode and the transition of irradiation intensity between the above two areas are successive, being interposed with a melting threshold level.