METHOD AND APPARATUS FOR MINIMIZING OVERLAY ERRORS IN LITHOGRAPHY

The invention relates to a method for minimizing errors of a plurality of photolithographic masks, the plurality of photolithographic masks serving for successively processing a substrate, the method comprises determining a reference displacement vector field, the reference displacement vector field correlates displacement vectors of the errors of the plurality of photolithographic masks, determining for each of the photolithographic mask a difference displacement vector field as a difference between the reference displacement vector field and the displacement vectors of the errors of the respective photolithographic mask, and correcting the errors for each of the photolithographic masks using the respective difference displacement vector field.