Patent ID: 7279252

Claim:
A process of manufacturing a substrate for a component used in EUV micro-lithography, comprising the following steps: providing a base layer consisting of a lithium-aluminosilicate glass ceramic having a coefficient of thermal expansion of no more than 0.1 ppm/K between 0° C. and 50° C.; polishing said base layer to a surface roughness of one nanometer rms at the most; applying a first cover layer consisting of silicon onto said base layer by ion beam sputtering up to a layer thickness between 20 nanometers and 200 nanometers; treating said first cover layer by a method selected from the group formed by ion beam figuring (IBF) and by magneto-rheologic polishing; applying a second cover layer comprising an organic lacquer up to a layer thickness between 20 and 200 nanometers; curing said second cover layer; at least partially removing said second cover layer by a method selected from the group formed by IBF and by magneto-rheologic polishing until a desired surface characteristic is reached.