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. 10, 2018
Filed:
Jul. 02, 2014
Heraeus Quarzglas Gmbh & Co. KG, Hanau, DE;
Klaus Becker, Hanau, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
A method for producing a mirror substrate blank made from titanium-doped silica glass for EUV lithography, having a thickness of at least 40 millimeters, includes steps of face grinding the surface of the blank and identifying data on defects in a surface layer of the blank. Light penetrates the blank at a predetermined angle of incidence α of less than 90° at a location on the flat surface of the blank. The light scatters on a defect in the blank, and the scattered light is detected at a distance x from the penetration location on the surface of the blank by a light detection element arranged perpendicularly thereabove. The method further includes steps of determining the position of the defect in the surface layer based on the obtained data, and partial or complete removal of the surface layer in consideration of the position determination and forming the mirror substrate blank.