Patent ID: 7088424

Claim:
A lithographic projection apparatus, comprising: a radiation system configured to form a beam of radiation from radiation emitted by a radiation source; a support configured to hold a patterning device, the patterning device configured to pattern the beam of radiation, a substrate table configured to hold a substrate; and a projection system configured to project the patterned beam of radiation onto a target portion of the substrate, wherein the radiation system comprises a reflector assembly placed in the vicinity of the source or an image of the source, the reflector assembly comprising a first reflector and a second reflector extending in the direction of an optical axis on which the source or an image of the source is located, the first and second reflector each having a reflective surface, a backing surface and an entry section, rays deriving from the source and intersecting the entry sections of the first and second reflectors being reflected on the reflective surface of the first reflector and defining a high radiation intensity zone and a low radiation intensity zone between the reflectors; and an actuator configured to adjust the position of at least one of the first reflector and the second reflector.