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. 12, 2013
Filed:
Jun. 13, 2013
Hoya Corporation, Tokyo, JP;
Yuki Shiota, Tokyo, JP;
Osamu Nozawa, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A photomask blank includes a transparent substrate and a film containing at lease two layers formed on the transparent substrate, the two layers being a first layer with a phase difference Δθand a second layer with a phase difference Δθ. The phase difference Δθis a phase difference between a light transmitted through the first layer and a light transmitted through an air distance equal to a thickness of the first layer, and the phase difference Δθis a phase difference between a light transmitted through the second layer and a light transmitted through an air distance equal to a thickness of the second layer. A phase difference of the film containing at least two layers is from −30° to +30°. The first layer contains a material not to be etched during etching of the transparent substrate.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile