| 摘要 |
A method of making a high-precision optical surface which may be used either as a Wolter-type segment in an X-ray mirror system or in a collector of a EUVL system or as a spherical, aspherical, or free form normal or grazing incidence mirror in an EUVL system is prepared by sagging a thin flat glass sheet onto a masterpiece, in particular a mandrel, made from a temperature-resistant material, such as an alumina based ceramic or a keatite glass ceramic. The glass sheet is polished to the desired surface roughness ( 14 ), is positioned to an upper surface of the masterpiece ( 16 ), and is heated ( 18 ) to effect sagging onto the upper surface of the masterpiece for generating a shaped body. Thereafter, the shaped body is cooled and removed from the masterpiece, is mounted within a holder ( 22 ), is inspected for deviations from the specification ( 24 ) preferably using interferometric measurements, and is corrected for defects ( 26 ), preferably using ion beam figuring.
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