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:
Jul. 03, 2007
Filed:
Nov. 29, 2004
Rene Oesterholt, 's-Hertogenbosch, NL;
Ralph Brinkhof, Eindhoven, NL;
Tjarko Adriaan Rudolf Van Empel, Eindhoven, NL;
Leon Martin Levasier, Hedel, NL;
Joost Jeroen Ottens, Veldhoven, NL;
Koen Jacobus Johannes Maria Zaal, Eindhoven, NL;
Koenraad Stephan Silvester Salden, Breda, NL;
Rene Oesterholt, 's-Hertogenbosch, NL;
Ralph Brinkhof, Eindhoven, NL;
Tjarko Adriaan Rudolf Van Empel, Eindhoven, NL;
Leon Martin Levasier, Hedel, NL;
Joost Jeroen Ottens, Veldhoven, NL;
Koen Jacobus Johannes Maria Zaal, Eindhoven, NL;
Koenraad Stephan Silvester Salden, Breda, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A lithographic system includes an illumination system for providing a projection beam of radiation, a mask table for supporting a mask, the mask serving to impart the projection beam with a pattern in its cross-section, a substrate table for holding a substrate, and a projection system for projecting the patterned beam onto a target portion of the substrate. The system also comprises a processor arranged to calculate overlay corrections using a reference height map representing a surface of the substrate table or the mask table. Feed forward correction of non-flatness induced wafer grid distortion is allowed during alignment and during exposure, thereby reducing overlay errors caused by differences in flatness characteristics. It provides an indirect qualification method for overlay accuracy related to exposure chuck flatness based on height map information.