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. 22, 1993
Filed:
Dec. 23, 1991
Tsuneo Terasawa, Ome, JP;
Masaaki Itou, Higashimurayama, JP;
Shigeo Moriyama, Tama, JP;
Soichi Katagiri, Hachioji, JP;
Hiroshi Fukuda, Kodaira, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In printing patterns on a mask onto a wafer with high accuracy via a reflective reduction projection optical system by using an X-ray or vacuum ultraviolet beam there is an elliptical mirror having a source position defined in an X-ray source and a position of reflection image of entrance pupil of an imaging optical system with respect to the mask as foci and introducing means for synchronously scanning the mask and wafer. Due to inserting a plane mirror for bending an X-ray by approximately 90.degree. at at least one point in the imaging optical system so that the plane of incidence may be perpendicular to the polarization plane the reflectivity does not lower even when the angle of incidence is 45.degree.. A reflecting mirror or an X-ray filter having a lower reflectivity in the peripheral part thereof as compared with the reflectivity of the central part thereof in the stop position of the imaging optical system, brings about an effect of lessened influence of mutual interference between adjacent pattern provides pattern printing with high shape accuracy.