Patent ID: 7223644

Claim:
A method of manufacturing a polycrystalline silicon film by crystallizing a silicon film, the method comprising: simultaneously irradiating a first irradiated region on the silicon film with pulsed visible laser light focused to have a linear shape, and a second irradiated region on the silicon film, partially overlapping the first irradiated region, with pulsed ultraviolet laser light; moving the silicon film relative to the visible and ultraviolet laser light in a movement direction perpendicular to a longitudinal direction of the linear shape of the pulsed visible laser light, wherein a part of the first irradiated region precedes the second irradiated region, along the movement direction; and repeating simultaneously irradiating the first and second irradiated regions and moving the silicon film relative to the visible and ultraviolet laser light so that regions subsequently irradiated overlap regions previously irradiated, along the movement direction.