POSITION DEVIATION DETECTION METHOD ND ALIGNER

摘要

PURPOSE:To accurately detect a position deviation by applying a laser beam for alignment which is applied from a diagonal direction to a mask surface to the alignment mark consisting of a rectangular pattern arrangement and detecting the position deviation using diffraction light toward the incidence side by the alignment mark. CONSTITUTION:A laser beam 6 introduced by an incidence optical system 5 is shed on alignment marks 3 and 4 at an angle being slanted by 12 degrees from a normal direction to a mask surface, generating diffraction light by the alignment marks 3 and 4. Diffraction lights 7 and 8 diffracted at an angle of approximately 21 degrees at the same side of the incidence light 6 for the normal direction of the mask out of the diffraction lights are detected by detection optical systems 9 and 10 which are formed in one piece with an incidence optical system 5. The phases of the detected diffraction light are compared, thus detecting the amount of position deviation between an Si wafer 1 and an X-ray mask.