SURFACE CORRECTION OF MIRRORS WITH DECOUPLING COATING

摘要

The invention relates to a mirror (1) for EUV lithography, comprising a substrate (2) and a reflective coating (3, 4), wherein the reflective coating comprises a first group (3) of layers (3a, 3b) and a second group (4) of layers (4a, 4b), wherein the first group (3) and second group (4) of layers (3a, 3b; 4a, 4b) are designed in each case for reflecting radiation having a used wavelength in the range of between 5 nm and 30 nm, wherein the first group (3) of layers (3a, 3b) is arranged between the substrate (2) and the second group (4) of layers (4a, 4b), and wherein a decoupling coating (6) is arranged between the first group (3) and second group (4) of layers (3a, 3b, 4a, 4b), said decoupling coating being designed for optically decoupling the second group (4) of layers (4a, 4b) from the first group (3) of layers (3a, 3b) by preventing the radiation having the used wavelength from reaching the first group (3) of layers (3a, 3b). The reflective coating (3, 4) preferably has a correction layer (5) having a layer thickness variation for correcting the surface form of the mirror (1). The invention also relates to a projection optical unit and an optical system for EUV lithography comprising at least one such mirror, a method for correcting the surface form of such a mirror, and methods for correcting the imaging properties of such a projection optical unit.