Patent ID: 7651825

Claim:
A method of determining an overlay alignment between a first layer layout and a second layer layout that are manufactured on a target portion of a substrate by lithographic processing, wherein the substrate includes a plurality of adjacent target portions, wherein the method comprises: forming at least one first overlay portion on the first layer layout; forming at least one first complementary overlay portion on the second layer layout, wherein the at least one first overlay portion and the at least one first complementary overlay portion are arranged to form an overlay mark; forming a stitching overlay portion on the second layer layout; forming a complementary stitching overlay portion on the second layer layout; exposing the second layer layout on the target portion of the substrate; exposing the second layer layout on at least one of the plurality of adjacent target portion that is located adjacent to the target portion; forming a stitching overlay mark from the exposure of the stitching overlay portion and the complementary stitching overlay portion; determining a stitching overlay for the target portion of the substrate; exposing the first layer layout over the second layer layout; and determining an overlay alignment of the first layer layout and the second layer layout.