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 cleaning arrangement is configured to clean an EUV optic of an EUV lithographic apparatus. The partial radical pressure ranges between 0.1-10 Pa. The cleaning arrangement can be configured inside a cleaning cocoon of the lithographic apparatus for offline cleaning. It can also be configured at particular positions inside the apparatus to clean nearby optics during production. In the pressure range of 0.1-10 Pa the penetration of atomic hydrogen into the optical devices is high, while the recombination to molecular hydrogen and hydrogen consumption is limited.

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 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: A multi-layer mirror includes on top of the multi-layer mirror a spectral purity enhancement layer, for example for application in an EUV lithographic apparatus. This spectral purity enhancement layer includes a first spectral purity enhancement layer, but between the multi-layer mirror and first spectral purity enhancement layer there may optionally be an intermediate layer or a second spectral purity enhancement layer and intermediate layer. Hence, multi-layer mirrors with the following configurations are possible: multi-layer mirror/first spectral purity enhancement layer; multi-layer mirror/intermediate layer/first spectral purity enhancement layer; and multi-layer mirror/second spectral purity enhancement layer/intermediate layer/first spectral purity enhancement layer. The spectral purity of normal incidence radiation may be enhanced, such that DUV radiation is diminished relatively stronger than EUV radiation.

Abstract: A multi-layer mirror includes on top of the multi-layer mirror a spectral purity enhancement layer, for example for application in an EUV lithographic apparatus. This spectral purity enhancement layer includes a first spectral purity enhancement layer, but between the multi-layer mirror and first spectral purity enhancement layer there may optionally be an intermediate layer or a second spectral purity enhancement layer and intermediate layer. Hence, multi-layer mirrors with the following configurations are possible: multi-layer mirror/first spectral purity enhancement layer; multi-layer mirror/intermediate layer/first spectral purity enhancement layer; and multi-layer mirror/second spectral purity enhancement layer/intermediate layer/first spectral purity enhancement layer. The spectral purity of normal incidence radiation may be enhanced, such that DUV radiation is diminished relatively stronger than EUV radiation.

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.

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.