Field facet system and lithography apparatus

Abstract

A field facet system for a lithography apparatus comprises: an optical element comprising a base body and an elastically deformable facet portion connected to the base body and having a light-reflecting optically active surface; and a plurality of actuating elements for deforming the facet portion to change a radius of curvature of the optically active surface. The actuating elements are operatively connected to the facet portion to isolate a heat induced deflection of the actuating elements from the facet portion so that the radius of curvature is not affected by the heat-induced deflection of the actuating elements.

Dependencies are inferred from the claim text.