Patent ID: 6728043
Filing Date: 2004-04-27
Classification: G03F,Y10S

Abstract:
A method for imaging a pattern arranged in an object plane of a projection lens onto an image plane of the projection lens comprising:illuminating the pattern with light for creating a light beam with a first light ray having a first polarization direction and a second light ray having a second polarization direction that differs from the first polarization direction; transmitting the light beam through the projection lens, wherein the light rays of the light beam are incident on the optical components of the projection lens at differing angles of incidence and wherein a difference in the lengths of a first optical path traversed by the first light ray and a second optical path traversed by the second light ray occurs within at least one region of the image plane due to the optical configuration employed; and compensating for the difference in optical path length by intentionally altering at least one of the first optical path and the second optical path such that the difference in the length of the optical path traversed by the first light ray and the length of the optical path traversed by the second light ray occurring within the image plane is largely independent of the angles of incidence of the light rays.