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. 28, 2026
Filed:
Jan. 21, 2022
Applicant:
Hoya Corporation, Tokyo, JP;
Inventors:
Hitoshi Maeda, Tokyo, JP;
Osamu Nozawa, Tokyo, JP;
Assignee:
HOYA CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03F 1/32 (2012.01);
U.S. Cl.
CPC ...
G03F 1/32 (2013.01);
Abstract
A mask blank comprises a transparent substrate and a phase shift film on the transparent substrate. The phase shift film includes a lower layer and an upper layer formed on the lower layer. The upper layer is in contact with the lower layer. The lower layer includes silicon and oxygen. The upper layer includes hafnium and oxygen. The upper layer has a thickness of 5 nm or more. The phase shift film has a thickness of 90 nm or less.