PROJECTION LENS WITH NON- ROUND DIAPHRAGM FOR MICROLITHOGRAPHY

摘要

A projection lens for microlithography comprises a diaphragm (BL) which is arranged at a distance (D) in front of a mirror (S2) of the lens. The diaphragm (BL) has an aperture (28) having an edge contour which is extended (28') in a non-round manner according to the inclination of the principal ray (34) and according to the distance (D) between the diaphragm (BL) and the mirror (S2).