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:
Sep. 22, 2009
Filed:
Sep. 29, 2005
Applicants:
Masaru Tanabe, Tokyo, JP;
Atsushi Kawaguchi, Tokyo, JP;
Hiroyuki Akagawa, Tokyo, JP;
Akihiro Kawahara, Tokyo, JP;
Inventors:
Masaru Tanabe, Tokyo, JP;
Atsushi Kawaguchi, Tokyo, JP;
Hiroyuki Akagawa, Tokyo, JP;
Akihiro Kawahara, Tokyo, JP;
Assignee:
Hoya Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03F 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a mask blank substrate to be chucked by a mask stage of an exposure system, the flatness of a rectangular flatness measurement area excluding an area of 2 mm inward from an outer peripheral end surface on a main surface of the mask blank substrate on its side to be chucked by the mask stage is 0.6 μm or less, and at least three of four corner portions of the flatness measurement area each have a shape that rises toward the outer peripheral side.