Reflective optical imaging system for extreme ultraviolet wavelengths
April 9, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3527526 3748015 Apparatus for microscopically viewing a specimen while detecting radiation particles therefrom All-reflective three element objective Restricted off-axis field optical system Imaging optical system Four mirror afocal wide field of view optical system Reflection type reduction projection optical system Projection optical system for use in precise copy High magnification reflecting microscope objective having a dual magnification mode and zoom magnification capability InventorsAssigneeApplicationNo. 682780 filed on 04/09/1991US Classes:359/355, Lens, lens system or component359/859With concave and convex mirrors in seriesExaminersPrimary: Arnold, Bruce Y.Assistant: Shafer, Ricky D. Attorney, Agent or FirmForeign Patent References
International ClassG02B 005/10AbstractA projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 μm, and preferably less than 100 μm. An image resolution of features less than 0.05-0.1 μm, is obtained over a large area field; i.e., 25.4 mm ×25.4 mm, with a distortion less than 0.1 of the resolution over the image field.Other References
Field of SearchLens, lens system or componentTwo or more in a series Concave, convex combination Including a nonspherical surface Conical With reflecting element Including concave or convex reflecting surface With aspheric surface (e.g., Schmidt lens, etc.) With concave and convex reflectors in series Reflectors in series With concave and convex reflectors in series Including curved mirror surfaces in series With concave and convex mirrors in series With three or more successive reflections With mirror surface of varied radius | |
