The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 2016
Filed:
Jan. 24, 2011
Boris Menchtchikov, Eindhoven, NL;
Alexander Viktorovych Padiy, Geldrop, NL;
Boris Menchtchikov, Eindhoven, NL;
Alexander Viktorovych Padiy, Geldrop, NL;
ASML Netherlands B.V., Veldhoven, NL;
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 model parameters, 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 model parameters. This results in a product wafer being exposed with a well controlled overlay.