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. 11, 2006
Filed:
Oct. 18, 2005
Jeffrey M. Hoffman, Tucson, AZ (US);
James P. Mcguire, Jr., Pasadena, CA (US);
Jeffrey M. Hoffman, Tucson, AZ (US);
James P. McGuire, Jr., Pasadena, CA (US);
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A lithographic apparatus includes a projection system, which includes a plurality of cubic crystalline optical elements that each impart retardance to a beam of radiation. The optical elements are aligned along an optical axis of the projection system and include two adjacent crystalline optical elements having a common crystalline lattice direction oriented along the optical axis. A first of the two adjacent elements is rotated about the optical axis with respect to a second of the adjacent elements with a predetermined rotation angle. The crystalline optical elements are selected and positioned along the optical axis and the rotation angle is selected such that, for each of two substantially perpendicular polarization states of the beam of radiation having a radiation wavelength of about 193 nm, the patterned beam of radiation has less than about 0.012 waves RMS of wavefront aberration across an exit pupil of the projection system.