Patent ID: 8953173
Filing Date: 2015-02-10
Classification: G03F

Abstract:
1. An apparatus for microlithographic projection exposure comprising: an optical system comprising a plurality of optical elements and configured to image mask structures onto a surface of a substrate by projecting the mask structures with an exposure beam of imaging radiation having an extreme ultraviolet or shorter wavelength onto an exposure area of the substrate surface, wherein the optical system is a catoptric system, and structure defining a measurement beam path and configured to guide measurement radiation, the measurement beam path extending within the optical system such that the measurement radiation impinges onto a measurement area of the substrate surface, wherein the apparatus is configured as a scanner, wherein during an exposure operation performed by the apparatus, the exposure area on the substrate surface is exposed by the exposure beam while the substrate is moved relative to the exposure beam in a scanning direction, thereby displacing the exposure area on the substrate surface, and wherein the measurement beam path is configured such that the measurement area moves, offset from the exposure area, on the substrate surface during the exposure operation.