Patent ID: 7312418

Claim:
A semiconductor thin film forming system for modifying a predetermined region of a semiconductor thin film by exposing the semiconductor thin film to a projected light, from an irradiation optical system, patterned through an exposure pattern formed on a photo mask, said semiconductor thin film being formed on a substrate held on a substrate stage, said system comprising: a first mechanism for sequentially scanning the semiconductor thin film with the patterned light by driving at least one of the photo mask and the substrate stage; a second mechanism for measuring a distance of a periphery of the substrate relative to the irradiation optical system; a third mechanism for measuring a tilt orientation of a periphery of the substrate relative to the irradiation optical system; a fourth mechanism for altering the distance of the periphery of the substrate relative to the irradiation optical system, thereby focusing the projected light; and a fifth mechanism for altering the tilt orientation of the periphery of the substrate relative to the irradiation optical system.