A process for the determination of focal plane deviation uniquely due to the lens field curvature associated with a photolithographic projection tool is described. A series of lithographic exposures is performed on a resist coated silicon wafer using a stepper or scanner running in static mode. The lithographic...http://www.google.de/patents/US7295291?utm_source=gb-gplus-sharePatent US7295291 - Apparatus and process for the determination of static lens field curvature
