US 7,023,523 B2 · Exposure system and exposure method

Abstract

Exposure systems are disclosed having a configuration in which a field stop is positioned in proximity to a reflection-type mask, but that satisfactorily minimize adverse effects on the image-forming performance of the projection-optical system. The systems transfer a mask pattern accurately and with high throughput onto a photosensitive substrate. The system comprises an illumination-optical system (1, 2) that illuminates a reflection-type mask (M) on which is formed a prescribed pattern. A projection-optical system forms an image of the mask pattern on the photosensitive substrate (W). The mask and substrate are moved in a prescribed direction relative to the projection-optical system to project the mask pattern onto and expose the photosensitive substrate. The illumination-optical system has a field stop (19), positioned in proximity to the mask, that defines the illumination area on the mask. The interval between the mask and the field stop satisfies a prescribed conditional relation.

Claims6

Dependent claims

An exposure system, comprising:

an illumination-optical system situated and configured to irradiate an illumination light on a reflective-type mask on which is formed a prescribed mask pattern, the illumination-optical system having a mask-side numerical aperture NA;
a projection-optical system situated and configured to form an image of the illuminated mask pattern on a photosensitive substrate;
the mask and the photosensitive substrate being respectively movable in a prescribed direction relative to the projection-optical system to project the illuminated mask pattern onto and expose the photosensitive substrate;
and
the illumination-optical system comprising a field stop, positioned in proximity to but separated by a distance in from the mask and defining an illumination area on the mask, the field stop having an aperture portion having a width dimension w in a prescribed direction;
wherein the following condition is satisfied:
in<0.5×w/(2×NA+an),
wherein an is an angle of incidence (in radians) on the mask of a principal ray of the illumination light illuminating the mask.

5 more elements

Dependencies are inferred from the claim text.

Exposure system and exposure method

Life of this patent

Exposure system and exposure method

Life of this patent

Abstract

Claims6