METHOD OF CORRECTING LITHOGRAPHY PROJECTION OBJECTIVE, AND THE OBJECTIVE

PROBLEM TO BE SOLVED: To provide a method of correcting at least one image defect of a catadioptric projection objective. SOLUTION: The method is provided for correcting at least one image defect in a projection objective 20 of a lithography projection exposure machine. The projection objective 20 comprises an optical arrangement equipped with multiple lenses and at least one mirror. At least one mirror has an optically operative surface that can be defective and is thus responsible for at least one image defect. The method comprises a step of at least approximately determining a ratio VM of principal ray height hMH to marginal ray height hMR at the optically operative surface of at least one mirror; and a step of approximately determining at least one optically operative surface among the lens surfaces of the lenses, at which the magnitude of a ratio VL of principal ray height hLH to marginal ray height hLR at least comes closest to the ratio VM. COPYRIGHT: (C)2007,JPO&INPIT