A surface position detecting system for detecting a surface position of a substrate. The system includes a plurality of sensors for measuring surface position at plural locations on the substrate, while relatively scanning the substrate, a discriminating device for discriminating and memorizing, beforehand,...http://www.google.es/patents/US6534777?utm_source=gb-gplus-sharePatente US6534777 - Surface position detecting system and method having a sensor selection
Surface position detecting system and method having a sensor selection
