Patent ID: 7161658
Filing Date: 2007-01-09
Classification: G03F

Abstract:
1. A lithographic apparatus comprising: an illumination system for providing a beam of radiation; a support structure for supporting a patterning device, the patterning device serving to impart the beam of radiation with a pattern in its cross-section; a substrate table for holding a substrate; and a projection optics assembly for projecting the patterned beam onto a target portion of the substrate, said projection optics assembly comprising a plurality of movable optical elements and a plurality of sensor units for sensing a position and/or orientation of a respective optical element, said movable optical elements being arranged in a spaced relationship on a support frame, said support frame comprising an assembly of at least two interconnected segments, each of said segments movably mounting at least one of said optical elements and fixedly mounting at least one of said sensor units, wherein said at least two interconnected segments serve as a reference and mounting frame within which said optical elements are mounted in said spaced relationship.