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:
Apr. 06, 1999
Filed:
Apr. 17, 1997
Masato Shibuya, Ohmiya, JP;
Keiichiro Sakato, Kawasaki, JP;
Akira Miyaji, Tokyo, JP;
Toshiyuki Namikawa, Kamagaya, JP;
Takashi Mori, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Apparatus and methods are disclosed for increasing the illuminance at a mask used for proximity-type microlithography and for achieving increases in throughput. A mask defining a pattern is illuminated by an illumination optical system. The pattern is transferred to a workpiece separated from the mask by a prescribed standoff. The mask and workpiece can be relatively moved in a scan direction. With respect to the illumination optical system, the workpiece-side numerical aperture in a first direction on the plane of the mask is different from the workpiece-side numerical aperture in a second direction, perpendicular to the first direction, on the plane of the mask. A reflective-type relay optical system can be included that comprises first and second spherical mirrors that do not produce chromatic aberrations.