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:
Feb. 25, 2020
Filed:
Dec. 24, 2015
Hoya Corporation, Tokyo, JP;
HOYA CORPORATION, Tokyo, JP;
Abstract
A mask blank is provided, which makes it possible to form a fine transfer pattern in a light-semitransmissive film with high accuracy even if the light-semitransmissive film is made of a material containing silicon and a light shielding film is made of a material containing chromium. The mask blankhas a structure in which the light-semitransmissive film, etching mask film, and light shielding filmare laminated in this order on the transparent substrate. It is featured in that the light-semitransmissive filmis made of the material containing silicon, the etching mask filmis made of the material containing chromium, the light shielding filmis made of a material containing chromium and oxygen, and a ratio of the etching rate of the light shielding filmto the etching rate of the etching mask filmin the dry etching with an oxygen-containing chlorine-based gas is not less than 3 and not more than 12.