| US 7,602,504 B2 | ||
| Exposure apparatus and device manufacturing method | ||
| Miwako Ando, Utsunomiya (Japan); and Yoshinori Ohsaki, Utsunomiya (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Mar. 31, 2008, as Appl. No. 12/59,444. | ||
| Claims priority of application No. 2007-109576 (JP), filed on Apr. 18, 2007. | ||
| Prior Publication US 2008/0259349 A1, Oct. 23, 2008 | ||
| Int. Cl. G01B 11/02 (2006.01) | ||
| U.S. Cl. 356—515 | 9 Claims |
| 1. An exposure apparatus equipped with a projection optical system configured to project a pattern of an original onto a substrate,
the exposure apparatus comprising:
an interferometer configured to measure a wavefront in a first direction and a wavefront in a second direction of light passed
through the projection optical system;
a focus detecting unit configured to detect focus positions in the first and second directions of the projection optical system;
and
a calculating unit configured to calculate wavefront aberration of the projection optical system on the basis of the measurement
result of the interferometer and the detection result of the focus detecting unit.
|