Debris prevention system, radiation system, and lithographic apparatus

A radiation system comprising:

• a radiation source comprising a plasma produced discharge source configured to generate extreme ultraviolet radiation, the discharge source comprising a pair of electrodes configured to be provided with a voltage difference, and a discharge system constructed and arranged to produce a discharge between said pair of electrodes so as to provide a pinched plasma in a central area between said electrodes;
• and
• a debris prevention system constructed and arranged to prevent debris that emanates from the radiation source from propagating with radiation from the radiation source into or within a lithographic apparatus, the debris prevention system comprising
• an aperture that defines a maximum emission angle of the radiation coming from the radiation source;
• a first debris barrier having a radiation transmittance, the first debris barrier comprising a rotatable foil trap;
• and
• a second debris barrier having a radiation transmittance,
• wherein said first debris barrier is configured to cover a part of said emission angle and said second debris barrier is configured to cover another part of said emission angle.

A radiation system comprising

• a radiation source;
• a debris prevention system constructed and arranged to prevent debris that emanates from the radiation source from propagating with radiation from the radiation source into or within a lithographic apparatus, the debris prevention system comprising
• an aperture that defines a maximum emission angle of the radiation coming from the radiation source;
• a first debris barrier having a radiation transmittance, the first debris barrier comprising a rotatable foil trap;
• and
• a second debris barrier having a radiation transmittance,
• wherein the first debris barrier covers a part of said emission angle and said second debris barrier covers another part of said emission angle;
• and
• a collector that defines a collection angle over which light is collected,
• wherein said rotatable foil trap and said second debris barrier are arranged to mitigate debris substantially over the entire collection angle.

A lithographic apparatus comprising:

• an illumination system configured to condition a radiation beam;
• a support constructed to support a patterning device, the patterning device being configured to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam;
• a substrate table constructed to hold a substrate;
• a projection system configured to project the patterned radiation beam onto a target portion of the substrate;
• and
• a debris prevention system constructed and arranged to prevent debris that emanates from a radiation source from propagating with radiation from the radiation source into or within the lithographic apparatus, said debris prevention system comprising
• an aperture that defines a maximum emission angle of the radiation coming from the radiation source;
• a first debris barrier having a radiation transmittance, the first debris barrier comprising a rotatable foil trap;
• and
• a second debris barrier having a radiation transmittance,
• wherein said first debris barrier is configured to cover a part of said emission angle and said second debris barrier is configured to cover another part of said emission angle.