Abstract: A mirror for a microlithographic projection exposure apparatus, and a method for operating a deformable mirror. In one aspect, a mirror includes an optical effective surface (11), a mirror substrate (12), a reflection layer stack (21) for reflecting electromagnetic radiation incident on the optical effective surface, and at least one piezoelectric layer (16) arranged between the mirror substrate and the reflection layer stack and to which an electric field for producing a locally variable deformation is able to be applied by a first electrode arrangement situated on the side of the piezoelectric layer (16) facing the reflection layer stack, and by a second electrode arrangement situated on the side of the piezoelectric layer facing the mirror substrate. The piezoelectric layer has a plurality of columns spatially separated from one another by column boundaries, wherein a mean column diameter of the columns is in the range of 0.1 ?m to 50 ?m.

Abstract: A mirror for a microlithographic projection exposure apparatus, and a method for operating a deformable mirror. In one aspect, a mirror includes an optical effective surface (11), a mirror substrate (12), a reflection layer stack (21) for reflecting electromagnetic radiation incident on the optical effective surface, and at least one piezoelectric layer (16) arranged between the mirror substrate and the reflection layer stack and to which an electric field for producing a locally variable deformation is able to be applied by a first electrode arrangement situated on the side of the piezoelectric layer (16) facing the reflection layer stack, and by a second electrode arrangement situated on the side of the piezoelectric layer facing the mirror substrate. The piezoelectric layer has a plurality of columns spatially separated from one another by column boundaries, wherein a mean column diameter of the columns is in the range of 0.1 ?m to 50 ?m.