Method for producing a substrate for an optical element

Abstract

A method for producing a substrate (10) for an optical element (11) includes: introducing a starting material, preferably a metal or a semimetal, into a container and melting the starting material, producing a material body having a quasi-monocrystalline volume region (8) by directionally solidifying the molten starting material proceeding from a plurality of monocrystalline seed plates arranged in the region of a base of the container, and producing the substrate by processing the material body to form an optical surface (12). An associated reflective optical element (11), in particular for reflecting EUV radiation (14) includes: a substrate having an optical surface on which a reflective coating (13) is applied. The substrate is typically produced in accordance with the associated method and has a quasi-monocrystalline volume region (8).

Dependencies are inferred from the claim text.