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:
Jan. 01, 2013
Filed:
Nov. 18, 2009
Alexander Epple, Aalen, DE;
Heiko Feldmann, Aalen, DE;
Hans-juergen Rostalski, Oberkochen, DE;
Carl Zeiss SMT GmbH, Oberkochen, DE;
Abstract
An objective having a plurality of optical elements arranged to image a pattern from an object field to an image field at an image-side numerical aperture NA>0.8 with electromagnetic radiation from a wavelength band around a wavelength λ includes a number N of dioptric optical elements, each dioptric optical element i made from a transparent material having a normalized optical dispersionΔ(λ)−(λ+1 pm)for a wavelength variation of 1 pm from a wavelength λ. The objective satisfies the relation for any ray of an axial ray bundle originating from a field point on an optical axis in the object field, where sis a geometrical path length of a ray in an ith dioptric optical element having axial thickness dand the sum extends on all dioptric optical elements of the objective. Where A=0.2 or below, spherochromatism is sufficiently corrected.