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:
Dec. 18, 2007
Filed:
Apr. 13, 2007
Alexander Epple, Aalen, DE;
Paul Graeupner, Aalen, DE;
Winfried Kaiser, Aalen, DE;
Reiner Garreis, Aalen, DE;
Wilhelm Ulrich, Aalen, DE;
Alexander Epple, Aalen, DE;
Paul Graeupner, Aalen, DE;
Winfried Kaiser, Aalen, DE;
Reiner Garreis, Aalen, DE;
Wilhelm Ulrich, Aalen, DE;
Carl Zeiss SMT AG, Oberkochen, DE;
Abstract
A method of adjusting a projection objective permits the projection objective to be adjusted between an immersion configuration and a dry configuration with few interventions in the system, and therefore to be used optionally as an immersion objective or as a dry objective. The projection objective has a multiplicity of optical elements which are arranged along an optical axis of the projection objective, the optical elements comprising a first group of optical elements following the object plane and a last optical element following the first group, arranged next to the image plane and defining an exit surface of the projection objective which is arranged at a working distance from the image plane. The last optical element is substantially without refracting power and has no curvature or only slight curvature. The method comprises varying the thickness of the last optical element, changing the refractive index of the space between the exit surface and the image plane by introducing or removing an immersion medium, and preferably axial displacement of the last optical element in order to set a suitable working distance.