| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration in the measurement accuracy due to foreign matters adhered to the reference surface for calibration of a reticle surface position detecting system for measuring the surface shape of the reticle. SOLUTION: Since calibration of the reticle surface position detecting system RO is conducted through reflection of the light at the reflecting surface as the reference surface of the reticle reference plate 19 provided to a reticle stage RST, a measurement error is generated when foreign matters are adhered to the reflecting surface. Existence of foreign matters adhered to the reflecting surface can be checked using an alignment optical system AS allocated at the upper part of the reticle reference plate 19, by forming the reflection surface of the reticle reference plate 19 as the transparent surface. When adhesion of foreign matters is confirmed, calibration of the reticle surface position detecting system RO is conducted by shifting the reticle reference plate 19 to the surface where the foreign matters are removed or not adhered. COPYRIGHT: (C)2004,JPO |
