| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection optical system bringing about a desired focusing function by suppressing variation in focusing function in the exposing region of an optical system due to intrinsic birefringence, and to provide an aligner and a process for fabricating a device. SOLUTION: The projection optical system for focusing a light beam from the surface of an object to an exposing region on an image plane where the [111] axis concerning the crystal orientation of an isometric system crystal is oriented to the optical axis comprises such an optical element as the direction of an image is aligned with the scanning direction of the exposing region when one [100] axis concerning the crystal orientation of an isometric system crystal is projected to a plane perpendicular to the optical axis. COPYRIGHT: (C)2004,JPO |
