LITHOGRAPHIC PROJECTOR, METHOD FOR MANUFACTURING DEVICE, DEVICE MANUFACTURED THEREBY AND GAS COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a lithographic projector using two or more color interferometer devices by an arbitrary selection to accurately obtain a position of a movable table in the projector. SOLUTION: The lithographic projector comprises a flushing gas means for supplying a purge gas to a space for housing at least a part of the movable table. In this case, the purge gas is selected so that a leakage of the purge gas into an operating area of the interferometer device may not bring about a significant error of an interferometer measured value.