Patent ID: 6243159
Filing Date: 2001-06-05
Classification: G03F

Abstract:
A projection aligner for irradiating a mask on which a pattern is formed with an energy ray and projecting an image of said pattern onto a photosensitive material through a projection optical system, comprising:a cylindrical member for passing the image of said pattern;an optical member, having a weight, held in said cylindrical member to separate first and second spaces in said cylindrical member while the first and second spaces are kept in an air-tight state; andpressure adjusting means for adjusting pressures in said first and second spaces based on the weight of the optical member so that a force having substantially the same magnitude as gravity working on said optical member works on said optical member in an opposite direction to said gravity;wherein said pressure adjusting means is for adjusting the pressures in said first and second spaces so that a product of a pressure difference between said first and second spaces and an area of said optical member for passing the energy ray is substantially the same as gravity working on said optical member.