| 摘要 |
PROBLEM TO BE SOLVED: To check the state of a projection optical system by enabling optical characteristics of a projection optical system to be measured on a projection aligner body, by mounting an interferometer for optical characteristic measurement of a projection optical system on a projection aligner body. SOLUTION: A light source 6 which is different from an exposure light source 1 is arranged as a light source of an interferometer for wave source measurement of a projection optical system 16. A beam from the light source 6 is injected to an objective lens 12 passing through means 7 to 9 through mirrors 10, 11. The incident laser reflects in a final surface at a reticle side of the objective lens 12 and enters a CCD photosensitive surface 28 as a reference beam through the mirrors 10, 12 and a condenser 27. Meanwhile, after an incident laser passes through the objective lens 12 and is image on a wafer 17 by the projection optical system 16, it reflects at a spherical mirror 20 on a stage 19 and condenses to the wafer 17, and enters a CCD photosensitive surface through the projection optical system 16, the objective lens 12, the mirrors 10, 11 and a condenser system 27. The beam which passed through the projection optical system 16 can perform wave surface measurement of the projection optical system 16 since it interferes with the reference beam.
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