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:
Apr. 17, 2007
Filed:
Nov. 25, 2003
Alexandre M. Mayolet, Chartres, FR;
Michael A. Pell, Fountainebleau, FR;
Alexandre M. Mayolet, Chartres, FR;
Michael A. Pell, Fountainebleau, FR;
Schott AG, Mainz, DE;
Abstract
The method of making a high quality fluoride crystalline optical microlithography lens element blank includes crystallizing a fluoride crystalline member with dimension ≧200 mm from a melt, annealing the fluoride crystalline member and qualifying the resulting member for use as an optical microlithography lens element blank The fluoride crystalline optical lithography lens element blanks have multiple adjoining abutting crystalline subgrains with low boundary angles. The crystalline members made by the method are qualified for use as lens element blanks by a testing method including measuring their absorption spectra at 200 to 220 nm to determine absorbance at 205 nm and/or by making measurements of radiation diffracted by them.