In calibration of overlay performance of an immersion lithographic apparatus, two sets of overlay data are obtained from exposures carried out using normal and reversed meanders. The two data sets can then be used to eliminate effects due to wafer cooling....http://www.google.es/patents/US7426011?utm_source=gb-gplus-sharePatente US7426011 - Method of calibrating a lithographic apparatus and device manufacturing method
Method of calibrating a lithographic apparatus and device manufacturing method
