A method includes providing a wafer having a first grating structure and a second grating structure formed in a photoresist layer. At least a portion of the first and second grating structures is illuminated with a light source. Light reflected from the illuminated portion of the first and second grating...http://www.google.es/patents/US6774998?utm_source=gb-gplus-sharePatente US6774998 - Method and apparatus for identifying misregistration in a complimentary phase shift mask process
Method and apparatus for identifying misregistration in a complimentary ...
