Projection exposure apparatus including an optical characteristic detector for detecting a change in optical characteristic of a projection optical system and device manufacturing method using the same

摘要

A projection exposure apparatus including a projection optical system for projecting a pattern of a reticle onto a substrate, an optical characteristic detecting device for detecting a change in optical characteristic of the projection optical system, which change may result from the projection of the reticle pattern onto the substrate through the projection optical system, and a light detecting device for detecting at least one of (i) an intensity distribution of light from the reticle pattern, at a position adjacent to the reticle or adjacent to an imaging plane on which the reticle is to be imaged, and (ii) an intensity distribution of the light from the reticle pattern, at a position adjacent to a pupil plane of the projection optical system, wherein the optical characteristic detecting device is arranged to detect the amount of change in optical characteristic in accordance with the intensity distribution detected by the light detecting device.