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. 19, 1994
Filed:
Sep. 15, 1992
Kozo Mochiji, Hachioji, JP;
Hiroaki Oizumi, Kokubunji, JP;
Shigeo Moriyama, Tama, JP;
Shinji Okazaki, Urawa, JP;
Tsuneo Terasawa, Ome, JP;
Masaaki Itou, Higashimurayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Reduction projection type X-ray lithography with an exposing beam wavelength of 40-150A, longer than in conventional 1:1 proximity exposure, has a high-vacuum space. This would reduce wafer replacement work efficiency and contaminate optical mirrors with substances released by a resist decomposed during exposure except for separating an optical system chamber and a wafer exposing chamber by a differential pumping section and a thin-film window. Wafer exposure is under atmospheric pressure, improving productivity, accuracy of exposure and longevity of the optical devices.