公开(公告)号：SG173957A1

公开(公告)日：2011-09-29

申请号：SG2011005733

申请日：2011-01-26

Applicant: ASML NETHERLANDS BV

Inventor： MENCHTCHIKOV BORIS ,  PADIY ALEXANDER

Abstract: A lithographic exposure process is performed on a substrate using a scanner.The scanner comprises several subsystems. There are errors in the overlay arising from the subsystems during the exposure. The overlay errors are measured using a scatterometer to obtain overlay measurements. Modeling is performed to separately determine from the overlay measurements different subsets of estimated modelparameters, for example field distortion model parameters, scan/step direction model parameters and position/deformation model parameters. Each subset is related to overlay errors arising from a corresponding specific subsystem of the lithographic apparatus. Finally, the exposure is controlled in the scanner by controlling a specific subsystem of the scanner using its corresponding subset of estimated modelparameters. This results in a product wafer being exposed with a well controlled overlay. [Figure 9]