| 摘要 |
PROBLEM TO BE SOLVED: To reduce deviation values of a reflection member and a convex lens by a method a reflection member is arranged in a unit integrated with a convex lens and an object is observed to correct effect due to changes in the attitude of the reflection member. SOLUTION: A pattern on a reticle R forms an image on a wafer W at an exposure wavelength by a projection optical system PL and the reflected light RL thereof enters a convex lens CVL through the optical system PL. The lens CVL is integrated with a prism P having a total reflection surface of a mirror TRM surface and the image of the wafer W is formed at the position I' at a distance L from the reflection surface of the mirror TRM. When the integrated unit is inclined by an angleθunder the vibration, an incident light beam is inclined by an angleθthe same as the angleθof the inclination of the mirror TRM. This gives a deviation valueΔ1 =Ltanθattributed to the mirror TRM and a deviation valueΔ2 =-L1 tanθattributed to the lens LVC (wherein L1 represents a distance to the surface I' from the lens, -αangle of light beam inclined by parallel eccentricity of surface top) and the effect of the both is opposite in direction. That is, the effect is corrected by integrating the both to reduce the deviation values.
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