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:
Jul. 27, 2021
Filed:
Jul. 12, 2018
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Takuro Kosaka, Joetsu, JP;
Hideo Kaneko, Joetsu, JP;
Shigeo Irie, Joetsu, JP;
Naoki Kawaura, Joetsu, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
A photomask blank is provided comprising a transparent substrate, a first film of chromium-containing material on the substrate, and a second film of silicon/oxygen-containing material disposed contiguous to the first film. The second film includes a first layer contiguous to the first film and a second layer spaced apart from the first layer in film thickness direction. The oxygen content of the first layer is lower than the oxygen content of the second layer. During etching of the first film, this setting prevents an etching rate from ramping up at the interface between the first and second films.