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:
Nov. 27, 2012
Filed:
Jun. 23, 2011
Masaru Tanabe, Tokyo, JP;
Masaru Tanabe, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A substrate set is a mask blank substrate set including a plurality of substrates each for use in a mask blank for producing a photomask to be chucked on a mask stage of an exposure apparatus. In each of the substrates in the mask blank substrate set, a main surface, on the side where a thin film for forming a transfer pattern is to be formed, has a convex shape being relatively high at its center and relatively low at its peripheral portion. In each substrate, the flatness in a 142 mm square area, including a central portion, of the main surface is 0.3 μm or less and the difference upon fitting to a reference main surface of a reference substrate is 40 nm or less.