Patent ID: 7023524

Claim:
A lithographic apparatus, comprising: an illumination system configured to provide a beam of radiation; a support configured to support a patterning structure, the patterning structure configured to impart the beam of radiation with a pattern in its cross-section; a substrate table configured to hold a substrate; and a projection system configured to project the patterned beam onto a target portion of the substrate, the projection system having an intermediate focus wherein, the apparatus comprises, in or adjacent the intermediate focus, a radiation attenuator configured to attenuate the patterned beam; a variable aperture system configured to pass at least a part of the patterned beam; and/or a radiation measuring system configured to measure an intensity of the patterned beam, wherein the radiation attenuator comprises a uniformity correction device comprising a plurality of blades configured to block part of the patterned beam, the uniformity correction device being configured to enhance the uniformity of the intensity of the patterned beam on the substrate and to dynamically adjust a radiation transmittance of the patterned beam at selected locations and the radiation measuring system comprises an intensity monitor sensor.