GAS BEARING USED FOR VACUUM CHAMBER AND APPLICATION OF ITS LITHOGRAPHY PROJECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a bearing which is usable for supporting, etc., of a sliding seal plate for sealing the opening of a vacuum chamber of a lithography projection device and has durability. SOLUTION: The bearing 21 supplies air of several atm from a supply path 211 to the spacing between a vacuum chamber wall 11 and the seal plate 12 to create a high pressure region 214 and separates both members to a prescribed distance. The bearing allows the escape of the supplied air from a groove 212 to an atmosphere pressure in order to prevent the non-permissible leakage to the vacuum chamber V and in addition, the bearing sucks the air by a pump via a vacuum conduit 231 to maintain the residual leakage 1 at a permissible level.