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:
Nov. 25, 2008
Filed:
Sep. 08, 2005
Ulrich Wegmann, Koenigsbronn, DE;
Vladimir Kamenov, Essingen, DE;
Thomas Muelders, Erding, DE;
Toralf Gruner, Aalen-Hofen, DE;
Markus Mengel, Heidenheim, DE;
Ulrich Wegmann, Koenigsbronn, DE;
Vladimir Kamenov, Essingen, DE;
Thomas Muelders, Erding, DE;
Toralf Gruner, Aalen-Hofen, DE;
Markus Mengel, Heidenheim, DE;
Carl Zeiss SMT AG, Oberkochen, DE;
Abstract
In a method for improving the imaging properties of a projection objective of a microlithographic projection exposure apparatus, an appropriate illumination angle distribution adapted to a mask () to be projected is selected. Then locations () in an exit pupil of the projection objective (), which are illuminated under these conditions by projection light during a projection of the mask, are determined. For at least one image point, an actual value of an imaging quantity, e.g. a wavefront profile or a polarization state, is determined that influences the imaging properties of the projection objective. Finally, corrective measures are calculated such that the actual value of the imaging quantity approximates a desired value at these locations. In this last step, however, deviations of the actual value from the desired value are taken into account exclusively at said locations illuminated in the exit pupil.