| US 7,518,707 B2 | ||
| Exposure apparatus | ||
| Miyoko Kawashima, Haga-gun (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Mar. 03, 2006, as Appl. No. 11/366,558. | ||
| Claims priority of application No. 2005-058685 (JP), filed on Mar. 03, 2005. | ||
| Prior Publication US 2006/0197933 A1, Sep. 07, 2006 | ||
| Int. Cl. G03B 27/72 (2006.01) | ||
| U.S. Cl. 355—71 [355/53; 355/67] | 6 Claims |
| 1. An exposure apparatus comprising a projection optical system for projecting a pattern of a mask onto a plate to be exposed,
said projection optical system comprising:
a pupil filter that includes a first area arranged on a light axis of the projection optical system and a second area formed
outside of the first area,
wherein the mask is one of an alternating phase shift mask and a chromeless phase shift mask, and the pattern of the mask
satisfies:
(p/λ)·NA≤0.65,
where p is a half pitch of the pattern, λ is a wavelength of light illuminating the mask, and NA is an image-side numerical
aperture of the projection optical system,
wherein, at most, 1st order light of diffracted light, which is diffracted by the pattern satisfying (p/λ)·NA≧0.65, passes the first area and a
part of the diffracted light having one order of at least 2nd order light passes the second area, and
with respect to the light having one order among the at least 2nd order light of the diffracted light, a phase of the light that has passed the second area and a phase of the light that has
passed an area other than the second area of the pupil filter are inverted with each other, and
wherein the second area in the pupil filter exists only in a part where a distance from a center of the first area is at least
0.9 when a radius of a pupil of the projection optical system is 1.
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