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. 03, 2003
Filed:
May. 30, 2001
Tsuyoshi Murata, Kanagawa, JP;
Hitoshi Ishizawa, Kanagawa, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An optical element ( ) of the present invention is provided with an optical substrate ( ) and a multilayered optical thin film ( ) formed on the optical substrate ( ). An MgF layer ( ) of the multilayered optical thin film has a refractive index of 1.10 to 1.35, especially 1.15 to 1.25 with respect to a vacuum ultraviolet light beam having a wavelength of not more than 250 nm. Therefore, when the optical element ( ) is used together with an excimer laser light beam having a wavelength of, for example, 248 nm (KrF), 193 nm (ArF), or 157 nm (F ), excellent optical characteristics are exhibited concerning, for example, the reflectance (anti-reflection), the polarization characteristics, and the dependency on the angle of incidence. The MgF layer ( ) can be produced in accordance with the sol-gel method. The optical element is preferably used for a projection lens of an exposure apparatus which uses the excimer laser light beam as a light source.