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:
Apr. 02, 2013
Filed:
Jan. 18, 2011
Masahiro Hashimoto, Tokyo, JP;
Hiroyuki Iwashita, Tokyo, JP;
Takahiro Hiromatsu, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A mask blank includes a transparent substrate and a light-shielding film formed on the transparent substrate. The light-shielding film is made of a material composed mainly of a metal that is dry-etchable with a chlorine-based gas. A resist film is used to form a transfer pattern in the light-shielding film. An etching mask film is formed on an upper surface of the light-shielding film and is made of a material containing a transition metal, silicon, and at least one of nitrogen and oxygen. A content ratio of the transition metal to a total of the transition metal and the silicon in the etching mask film is less than 9%.