Method of manufacturing semiconductor thin film

Abstract

On a translucent substrate, an insulating film having a refractive index n and an amorphous silicon film are deposited successively. By irradiating the amorphous silicon film with a laser beam having a beam shape of a band shape extending along a length direction with a wavelength λ, a plurality of times from a side of amorphous silicon film facing the insulating film, while an irradiation position of the laser beam is shifted each of the plurality of times in a width direction of the band shape by a distance smaller than a width dimension of the band shape, a polycrystalline silicon film is formed from the amorphous silicon film. Forming the polycrystalline silicon film forms crystal grain boundaries which extend in the width direction and are disposed at a mean spacing measured along the length direction and ranging from (λ/n)×0.95 to (λ/n)×1.05 inclusive, and crystal grain boundaries which, in a region between crystal grain boundaries adjacent to each other and extending in the width direction, extend in the length direction and are disposed at a mean spacing measured along the width direction and ranging from (λ/n)×0.95 to (λ/n)×1.05 inclusive.