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:
Mar. 29, 2011
Filed:
Jul. 06, 2009
Applicants:
Hans-juergen Mann, Oberkochen, DE;
Martin Lowisch, Oberkochen, DE;
Wolfgang Singer, Aalen, DE;
Inventors:
Assignee:
Carl Zeiss SMT GmbH, Oberkochen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03F 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
One problem of projection optics concerns pupil apodization which leads to imaging defects. As here proposed, the illumination system is configured to illuminate the mask inhomogeneously. As a result, inhomogeneities in reflectivity caused by the mask itself are at least partly counteracted. This compensation not only makes the apodization over the pupil become more symmetric but also makes the intensity variation smaller overall.