| US 7,495,742 B2 | ||
| Measuring method and apparatus, exposure method and apparatus using the same, and device manufacturing method | ||
| Yoshinori Shiode, Tochigi (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Dec. 15, 2004, as Appl. No. 11/13,252. | ||
| Claims priority of application No. 2003-417212 (JP), filed on Dec. 15, 2003. | ||
| Prior Publication US 2005/0128447 A1, Jun. 16, 2005 | ||
| Int. Cl. G03B 27/68 (2006.01); G03B 27/42 (2006.01); G03B 27/32 (2006.01) | ||
| U.S. Cl. 355—52 [355/53; 355/77] | 7 Claims |
| 1. A method for measuring optical performance of a projection optical system in an exposure apparatus, said method comprising:
placing an illumination stop for oblique illumination, the illumination stop having a predetermined optimized shape in an
illumination optical system, wherein the shape of the illumination stop is optimized in accordance with a specific Zernike
term;
determining an area of a pupil in a pupil plane of the projection optical system based on said predetermined optimized shape;
scanning a test reticle or a reference plate;
imaging a test pattern on the test reticle or the reference plate onto a photosensitive substrate during said scanning step
via the area of said pupil which has been determined by said determining step, wherein light intensity distribution at the
determined area of said pupil is substantially similar to the predetermined optimized shape of said illumination stop; and
measuring a positional offset between a predetermined position of the test pattern and an image of the test pattern that has
been imaged by said imaging step,
wherein light that passes through the determined area of the pupil is restricted by the test pattern and the illumination
stop so that the positional offset of the test pattern image with respect to the predetermined position has a 1:1 relationship
with a coefficient of the specific Zernike term.
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