An alignment strategy for asymmetrical alignment marks in a wafer, in which the positions of the a symmetrical alignment marks are determined twice. A first set of positions is detected after a chemical-mechanical polishing step. A second set of positions is detected after a rotation in which the wafer...http://www.google.es/patents/US6074950?utm_source=gb-gplus-sharePatente US6074950 - Alignment strategy for asymmetrical alignment marks
Alignment strategy for asymmetrical alignment marks
