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:
Aug. 23, 2022
Filed:
Aug. 31, 2021
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
A phase shift mask blank has a transparent substrate and a phase shift film formed on the transparent substrate. The phase shift film has a phase difference of 160 to 200° and a transmittance of 3 to 15% at exposure wavelength of 200 nm or less and includes a lower layer and an upper layer in order from the transparent substrate side. The upper layer contains transition metal, silicon, nitrogen and/or oxygen, or silicon, nitrogen and/or oxygen. The lower layer contains chromium, silicon, nitrogen and/or oxygen, and the content of silicon is 3% or more to less than 15% for the sum of chromium and silicon in the lower layer. The ratio of oxygen content to the total content of chromium and silicon is less than 1.7, and etching selectivity of the upper layer is 10 or more compared to the lower layer in fluorine-based dry etching.