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. 18, 2010
Filed:
Nov. 18, 2008
Jin Nishikawa, Tokyo, JP;
Jin Nishikawa, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An illumination optical apparatus which illuminates an illumination objective surface with an exposure light includes: an illumination optical system having a curved mirror and a concave mirror and defining a position substantially conjugate with the illumination objective surface between the curved and concave mirrors; and a second aperture plate separating a space in which the curved mirror is arranged and a space in which the concave mirror is arranged into mutually different vacuum environments or pressure-reduced environments, and having an aperture through which the exposure light passes, the aperture being arranged at a position at which a cross-sectional area of the exposure light is smallest, or in the vicinity of the position. It is possible to decrease the amount of passage of minute particles such as debris in relation to any downstream-side optical system.