WAFER PERIPHERY EXPOSURE SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a wafer periphery exposure system whose focal point can be easily and safely controlled by a method wherein a positional relation between an exposure light beam irradiating means and a wafer in the direction in which an exposure light beam is projected is remotely controlled. SOLUTION: A lens unit 47 is composed of lenses such as condensing lenses prescribed in focal length and so formed as to be movable in a vertical direction together with a lens holder 46. A pole screw 51 driven and rotated by a Z-axis pulse motor 50 is provided under the bearing member of the lens holder 46, and the tapered tip of the pole screw 51 is made to push up the underside of the bearing member of the lens holder 46 as the pole screw 51 is rotated to ascend.