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:
Nov. 30, 2021
Filed:
Sep. 23, 2019
Toppan Printing Co., Ltd., Tokyo, JP;
TOPPAN PRINTING CO., LTD., Tokyo, JP;
Abstract
A photomask blank and a photomask having favorable wafer transfer characteristics and irradiation resistance. A photomask blank is for fabricating a photomask for an exposure wavelength of 193 nm, the photomask blank comprising: a light-transmissive substrate; a phase shift film formed on the light-transmissive substrate and providing phase shift effects of a light transmittance of at least 30% with respect to exposure light; and a light-shielding film formed on the phase shift film. The phase shift film is constituted by lamination of: a first phase shift film (that uses a silicon nitride-based material, has a refractive index n1 of 2.5 to 2.7, and an extinction coefficient k1 of 0.2 to 0.4; and a second phase shift film that uses a silicon oxynitride-based material, has a refractive index n2 of 1.55 to 2.20, and an extinction coefficient k2 greater than 0 but no greater than 0.1.