A method and apparatus for positioning a wafer with respect to a reticle in a projection exposure apparatus for a photolithographic process capable of high speed search alignment of a wafer without any limitation imposed on the arrangement of the search marks on the wafer. For the first wafer in one...http://www.google.com/patents/US6400445?utm_source=gb-gplus-sharePatent US6400445 - Method and apparatus for positioning substrate
