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:
Jun. 20, 2017
Filed:
Aug. 07, 2015
Asahi Glass Company, Limited, Chiyoda-ku, JP;
Yusuke Hirabayashi, Tokyo, JP;
ASAHI GLASS COMPANY, LIMITED, Chiyoda-ku, JP;
Abstract
A glass substrate for a mask blank has a rectangular planar shape. In four square regions each positioned at each corner of a first region (quality assurance region) and having one side of 8 mm, an angle between a least square plane in each the square region and that in the first region is 3.0 μad or less, and a PV value relative to the least square plane is 30 nm or less. In four strip regions each positioned in an area between one side of the first region and 8 mm inside the side and excluding the square regions, an angle between a least square plane in each the strip region and that in the first region is 1.5 μad or less, and a PV value relative to the least square plane is 15 nm or less.