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:
Feb. 17, 1998
Filed:
Sep. 06, 1996
Applicant:
Inventors:
Hiroyuki Hiraiwa, Yokohama, JP;
Issey Tanaka, Yokohama, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; C03C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
359355 ; 359350 ; 65413 ; 65 171 ; 501 53 ; 501905 ;
Abstract
Recent UV-lithography is required to provide a fine and sharp pattern with a line width of 0.5 .mu.m or less. The present invention provides a silica glass member adapted for use as an optical element for UV-lithography, by giving consideration to the RMS value of wave front aberration and the slant element of refractive index, which have not been considered in the art. Also, there is provided a silica glass member excellent in durability to the ultraviolet irradiation, by introduction of hydrogen molecules at the synthesis of the silica glass, instead of using a secondary treatment for hydrogen introduction.