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:
May. 13, 2008
Filed:
Jul. 18, 2006
Tammo Uitterdijk, Bilt, NL;
Laurentius Catrinus Jorritsma, Helmond, NL;
Tammo Uitterdijk, Bilt, NL;
Laurentius Catrinus Jorritsma, Helmond, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
An aberration correction device useable in lithography comprises two elements, at least one of which is relatively rotatable to the other about, for example, an optical axis. One surface of each element has an aspheric form describable by higher Zernike polynomials. When the two surfaces are rotationally aligned, the device has the optical effect of a plane plate. If there is a small relative rotation of the two elements the effect of the device is a phase shift describable by the derivative of the aspheric form. The correction device may be used to correct aberrations caused by lens heating, especially with illumination modes and pattern types resulting in strong off-axis localized pupil filling in the projection system.