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:
Mar. 10, 2009
Filed:
Apr. 13, 2006
Bodo Kuehn, Hanau, DE;
Stephan Ochs, Bad Camberg, DE;
Steffen Kaiser, Hanau, DE;
Denis Kassube, Rodenbach, DE;
Bodo Kuehn, Hanau, DE;
Stephan Ochs, Bad Camberg, DE;
Steffen Kaiser, Hanau, DE;
Denis Kassube, Rodenbach, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
To provide an optical component of quartz glass for use in a projection lens system for immersion lithography with an operating wavelength below 250 nm, which is optimized for use with linearly polarized UV laser radiation and particularly with respect to compaction and birefringence induced by anisotropic density change, it is suggested according to the invention that the quartz glass should show the combination of several properties: particularly a glass structure essentially without oxygen defects, a mean content of hydroxyl groups of less than 60 wt ppm, a mean content of fluorine of less than 10 wt ppm, a mean content of chlorine of less than 1 wt ppm. A method for producing such an optical component comprises the following method steps: producing and drying an SiOsoot body under reducing conditions and treating the dried soot body before or during vitrification with a reagent reacting with oxygen defects of the quartz glass structure.