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. 05, 2019
Filed:
Feb. 15, 2018
Agc Inc., Chiyoda-ku, JP;
Yuzo Okamura, Tokyo, JP;
Yusuke Hirabayashi, Tokyo, JP;
AGC Inc., Chiyoda-ku, JP;
Abstract
A mask blank includes a glass substrate including a first main surface and a second main surface, an absorbing film formed above the first main surface, and a conductive film formed on the second main surface. A reflective film is provided between the absorbing film and the glass substrate. In a surface of the conductive film on an opposite side to the glass substrate, when a surface shape of a square central area having a length of 142 mm and a width of 142 mm excluding a four-sided frame-shaped peripheral area thereof is expressed by the specific formula, flatness of a component obtained by summing all aP(x)P(y) with the sum of k and l being 3 or more and 25 or less is 20 nm or less.