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:
Sep. 22, 1998
Filed:
Oct. 01, 1996
Noriaki Tokuda, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A projection exposure apparatus according to the present invention (in particular, an excimer stepper) includes a projection optical system, which may include a lens element of synthetic quartz and a lens element of fluorite. The synthetic quartz lens element is temperature-controlled by a first temperature controller with a degree of accuracy of .+-.0.01.degree. C., for example. The fluorite lens element is temperature-controlled by a second temperature controller with a degree of accuracy of .+-.0.005.degree. C., for example. Therefore, even if the projection optical system includes lens elements with different coefficients of thermal expansion, temperature control can be made with accuracy suitable for each of the elements. Consequently, the apparatus is not enlarged. In addition, with an exposure light source of even short wavelength, it is possible to attain good imaging characteristics.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile