Patent ID: 8404498

Claim:
A method of forming a semiconductor thin film comprising: a step of forming an amorphous semiconductor thin film over a transparent substrate; a step of forming a crystalline semiconductor thin film by irradiating the amorphous semiconductor thin film with laser light to provide heat treatment and thereby crystallizing the amorphous semiconductor thin film; and an inspection step of inspecting the crystalline semiconductor thin film, wherein, the inspection step includes a step of obtaining a transmission image of the crystalline semiconductor thin film by irradiating the crystalline semiconductor thin film with light from a rear side of the transparent substrate and taking an image, and a screening step of performing screening of the crystalline semiconductor thin film based on the obtained transmission image, in the screening step, a width of a crystallized region is obtained based on the obtained transmission image, and a crystallization state of the crystalline semiconductor thin film is inspected according to the width of the crystallized region, and in the step of obtaining the transmission image, an irradiated light in the green light wavelength range is generated by an LED light source for inspecting the crystalline semiconductor thin film.