Method for manufacturing polycrystal semiconductor film

Abstract

There is disclosed a method for manufacturing a polycrystal semiconductor film comprising the steps of applying a high energy beam to a surface of a semiconductor film comprising an amorphous or a polycrystal semiconductor provided on a surface of a substrate to melt only the semiconductor film, and solidifying the film via a solid and liquid coexisting state to form a semiconductor film comprising a polycrystal semiconductor having a large grain diameter, by heating a liquid part using a difference in an electric resistance in the liquid and solid coexisting state to heat only the liquid part, and by extending the solidification time until the completion of solidifying of the molten liquid crystal film. Furthermore, as the base film of the semiconductor film, a material having a melting point of 1600.degree. C. and a thermal conductivity of 0.01 cal/cm.s..degree. C. is used to suppress heat dissipation from the molten liquid of the semiconductor to the substrate so that time until the complete solidification can be prolonged. Furthermore, the beam is irradiated so as to form a standing wave at a predetermined position of the surface of the semiconductor film to generate the heat density distribution having the same cycle with the standing wave and to melt the semiconductor film with the result that a polycrystal semiconductor film comprising a uniform and a large crystal grains by controlling the distribution of the crystal nuclei at the interface between the base film and the substrate.