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:
Jul. 07, 2015
Filed:
Mar. 30, 2010
Masahiro Hashimoto, Tokyo, JP;
Hiroyuki Iwashita, Tokyo, JP;
Yasushi Okubo, Tokyo, JP;
Osamu Nozawa, Tokyo, JP;
Masahiro Hashimoto, Tokyo, JP;
Hiroyuki Iwashita, Tokyo, JP;
Yasushi Okubo, Tokyo, JP;
Osamu Nozawa, Tokyo, JP;
HOYA CORPORATION, Tokyo, JP;
Abstract
A mask blank and transfer mask that overcomes problems caused by an electromagnetic field (EMF) effect when a DRAM half pitch (hp) is 32 nm or less specified in semiconductor device design specifications. The mask blank is used in manufacturing a transfer mask to which ArF exposure light is applied, and includes a light shielding filmhaving a multilayer structure. The multilayer structure includes a light shielding layerand a surface anti-reflection layerformed on a transparent substrate. An auxiliary light shielding filmis formed on the light shielding film. The light shielding filmhas a thickness of 40 nm or less and an optical density of 2.0 or more to 2.7 or less for exposure light. The optical density is 2.8 or more for exposure light in the multilayer structure of the light shielding filmand the auxiliary light shielding film