Patent ID: 6404499
Filing Date: 2002-06-11
Classification: G03F

Abstract:
A lithographic projection apparatus comprising:a radiation system comprising a source of radiation, said radiation system supplying a projection beam the cross-section of which in the plane of a mask is smaller than a mask pattern; a mask table being movable in at least a first direction and being provided with a mask holder in which the mask can be held; a projection system constructed and arranged to image an irradiated part of the mask pattern onto a substrate with a magnification M; a substrate table which is movable along the first direction and along a second direction perpendicular thereto, and is provided with a substrate holder in which the substrate can be held; a mask table drive device constructed and arranged to move the mask table during each imaging operation along at least the first direction, with respect to the projection beam and the projection system; a substrate table drive device constructed and arranged to move the substrate table during each imaging operation along at least the first direction at a rate equal to M times the rate at which the mask table is moved; and a correction device comprising a filter unit placed in the path of the projection beam, said filter unit varying the spatial intensity of the beam along at least one direction of its cross-section so that the integrated radiation intensity at substrate level is substantially uniform across substantially the entire length of that cross-section; and wherein said filter unit comprises a first member located in the path of the beam, said first member being a first filter which is movable along a movement axis; and wherein said first member further comprises a second filter, said second filter being movable relative to said first filter.