An assembly, a lithographic apparatus, and a device manufacturing method

摘要

A lithographic apparatus comprising a projection optics assembly PL for projecting a patterned beam onto a target portion of the substrate. The projection optics assembly comprising a first element 4 having a predetermined functionality which is to be fixedly positioned with respect to a second element 2, wherein the elements 4, 2 are arranged in a spaced relationship on a support frame 6, wherein the support frame 6 is provided with an interface surface 8 formed on or in said support frame 6 for receiving the first element 4, wherein the interface surface 8 determines the position of the first element 4 with respect to the second element 2, and is adapted in accordance with the predetermined functionality so that the first element 4 is positionable with respect to the second element 2 with at least three degrees of freedom.