Patent ID: 7145132

Claim:
A lithographic apparatus comprising: an illumination system configured to condition a radiation beam, the illumination system comprising a source for generating radiation; and a debris trapping system for trapping at least some debris particles released with the generation of radiation; a patterning device for patterning the conditioned radiation beam; and a projection system for projecting the patterned radiation beam onto a target portion of a substrate, wherein the debris trapping system comprises (i) a first set of channels, each channel of the first set enabling radiation from the source to propagate therethrough and having an inner wall for catching debris particles; (ii) a second set of channels, situated downstream of the first set of channels with respect to a propagation direction of the radiation, each channel of the second set enabling radiation from the source to also propagate and having an inner wall for catching debris particles; and (iii) a gas supply and a gas exhaust configured to provide between the first set of channels and the second set of channels a gas flow having a net flow direction substantially across the propagation direction of the radiation.