Abstract: A method of removing a deposition from an optical element of an apparatus. The method includes providing a hydrogen comprising gas in at least a part of the apparatus, providing nitrogen radicals in the part of the apparatus for generating hydrogen radicals from the hydrogen comprising gas, and contacting the optical element with at least part of the hydrogen radicals to removal the deposition.

Abstract: A lithographic apparatus includes a radiation system for providing a beam of radiation. The radiation system includes at least one of a contaminant trap for trapping material emanating from the radiation source and a collector for collecting the beam of radiation. The at least one of the contaminant trap and the collector includes an element arranged in the path of the radiation beam on which the material emanating from the radiation source can deposit during propagation of the radiation beam in the radiation system. At least a part of the element disposed in the path of the radiation beam has a surface that has a highly specular grazing incidence reflectivity to reduce the absorption of the radiation beam in a direction of propagation of the radiation beam substantially non-parallel to the surface of the element, so that a thermal load experienced by the element is reduced.

Abstract: A lithographic apparatus includes a collector configured to collect radiation from a radiation source, the collector including a plurality of shells forming separate compartments, and a cleaning arrangement including a gas inlet and a gas outlet, the cleaning arrangement being configured to clean surfaces of the plurality of shells by guiding a gas flow from the inlet through the compartments to the outlet. The cleaning arrangement includes a distribution system configured to divide the gas flow into several sub flows, each of the sub flows corresponding to one or more of the compartments, and a control system configured to control the relative amount of the sub flows.

Abstract: A radiation system for providing a projection beam of radiation is disclosed. The radiation system includes an extreme ultraviolet source for providing extreme ultra violet radiation, and a contamination barrier that includes a plurality of closely packed foil plates for trapping contaminant material coming from the radiation source. The contamination barrier encloses the extreme ultraviolet radiation source.

Abstract: A method for the removal of a deposition on an optical element of an apparatus including the optical element includes providing an H2 containing gas and one or more additional compounds selected from the group of hydrocarbon compounds and silane compounds in at least part of the apparatus includes producing hydrogen radicals from H2 from the H2 containing gas; and bringing the optical element with deposition into contact with at least part of the hydrogen radicals and removing at least part of the deposition. Further, a method for the protection of an optical element of an apparatus including the optical element includes providing a cap layer to the optical element by a deposition process; and during or after use of the apparatus, removing at least part of the cap layer from the optical element in a removal process as described above. The methods can be applied in a lithographic apparatus.

Abstract: A method for filtering particles out of a beam of radiation propagating from a radiation source is provided. The method includes passing the beam of radiation through a filter having a first portion within the beam of radiation and a second portion outside of the beam of radiation, capturing at least some of the particles in the beam of radiation with the first portion, and moving the filter in a direction that is transverse to the beam of radiation so that the first portion is moved outside of the beam of radiation and the second portion is moved into the beam of radiation.

Abstract: A lithographic apparatus is disclosed. The apparatus includes a source for supplying hydrogen radicals, a guide for use in conjunction with the source, for directing hydrogen radicals to an application surface to be targeted by the hydrogen radicals. The guide is provided with a coating having a hydrogen radical recombination constant of less than 0.2. In this way, the radicals can be transported with reduced losses and are able to better interact with remaining contaminants on application surfaces, such as mirror surfaces.

Abstract: An optical element including an anti-reflection (AR) coating is configured to reflect Extreme-Ultra-Violet (EUV) radiation only.

Abstract: A method for the removal of a deposition on an optical element of an apparatus including the optical element includes providing an H2 containing gas in at least part of the apparatus includes producing hydrogen radicals from H2 from the H2 containing gas; and bringing the optical element with deposition into contact with at least part of the hydrogen radicals and removing at least part of the deposition. Further, a method for the protection of an optical element of an apparatus including the optical element includes providing a cap layer to the optical element by a deposition process; and during or after use of the apparatus, removing at least part of the cap layer from the optical element in a removal process as described above. The methods can be applied in a lithographic apparatus.