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:
Jun. 29, 2021
Filed:
May. 16, 2018
Hoya Corporation, Tokyo, JP;
Masahiro Hashimoto, Tokyo, JP;
Hiroaki Shishido, Tokyo, JP;
HOYA CORPORATION, Tokyo, JP;
Abstract
This mask blank has a structure wherein a phase shift film and a light shielding film are sequentially formed as layers in this order on a transparent substrate. The optical density of the layered structure composed of the phase shift film and the light shielding film with respect to exposure light, which is an ArF excimer laser, is 3.5 or more; and the light shielding film has a structure wherein a lower layer and an upper layer are formed as layers sequentially from the transparent substrate side. The lower layer is formed from a material wherein the total content of chromium, oxygen, nitrogen and carbon is 90 atomic % or more; and the upper layer is formed from a material wherein the total content of metals and silicon is 80 atomic % or more. The extinction coefficient kof the upper layer for the exposure light is higher than the extinction coefficient kof the lower layer for the exposure light.