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:
May. 30, 2017
Filed:
Oct. 24, 2013
Hoya Corporation, Tokyo, JP;
HOYA CORPORATION, Tokyo, JP;
Abstract
Methods of manufacturing a mask blank and a transfer mask that reduce internal stress of a thin film. The methods include preparing a transparent substrate having a pair of opposing main surfaces and composed of a glass material having a hydrogen content of less than 7.4×1018 molecules/cm3, forming a thin film composed of a material containing silicon or metal on one of the main surfaces of the transparent substrate, and carrying out heating treatment or photo irradiation treatment on the transparent substrate with the thin film. The absolute value of a variation of flatness in a predetermined region, as calculated based on a difference in shape obtained from a shape of a main surface of the transparent substrate prior to forming the thin film and a shape of a main surface of the substrate exposed after removing the thin film, is not more than 100 nm.