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:
Dec. 25, 2007
Filed:
Nov. 08, 2006
Arie Jeffrey Den Boef, Waalre, NL;
Hans Van Der Laan, Veldhoven, NL;
Antonius Johannes Josephus Van Dijsseldonk, Hapert, NL;
Mircea Dusa, Campbell, CA (US);
Antoine Gaston Marie Kiers, Veldhoven, NL;
Arie Jeffrey Den Boef, Waalre, NL;
Hans Van Der Laan, Veldhoven, NL;
Antonius Johannes Josephus Van Dijsseldonk, Hapert, NL;
Mircea Dusa, Campbell, CA (US);
Antoine Gaston Marie Kiers, Veldhoven, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
In a method according to one embodiment of the invention, aberrations in a lithographic apparatus are detected by printing a test pattern having at least one degree of symmetry and being sensitive to a particular aberration in the apparatus, and using a scatterometer to derive information concerning the aberration. The test structure may comprise a two-bar grating, in which case the inner and outer duty ratios can be reconstructed to derive information indicative of comatic aberration. Alternatively, a hexagonal array of dots can be used, such that scatterometry data can be used to reconstruct dot diameters indicative of 3-wave aberration.