Patent ID: 7365345

Claim:
A lithographic apparatus comprising: a radiation system configured to form a projection beam of radiation comprising: (a) a radiation source that emits radiation; (b) a filter system arranged to filter debris particles out of a predetermined cross-section of the radiation emitted by the radiation source, the filter system including a first set of foils and a second set of foils for trapping the debris particles, and a first heat sink and a second heat sink, each foil of the first set of foils being thermally connected to the first heat sink, and each foil of the second set of foils being thermally connected to the second heat sink, so that heat is conducted substantially towards the first heat sink through each foil of the first set, and heat is conducted substantially towards the second heat sink through each foil of the second set, the first set of foils extending substantially in a first section of the predetermined cross-section, and the second section of foils extending substantially in a second section of the predetermined cross-section, the first section and the second section being substantially non-overlapping; and (c) an illumination system configured to form the radiation emitted by the radiation source to a conditioned radiation beam; and a projection system configured to project the projection beam of radiation onto a substrate.