Abstract: A top layer of a predetermined metal is provided on a mirror for use in a lithographic apparatus having source to provide radiation of a desired wavelength. The source generates a stream of undesired metal particles that are deposited to form smaller and larger nuclei on the mirror. The top layer may interdiffuse in a predetermined temperature range with nuclei of the metal deposition. An additional layer of an alloy of the metal particles and the metal of the top layer is formed that has a higher reflectivity than a layer only comprising the metal particles would have.

Abstract: A method for manufacturing arid/or protecting an optical element, wherein the optical element has at least one surface comprising a profile having height differences, thereby providing cavities and elevations having a predetermined maximum height difference, includes providing a transmissive layer in the cavities and on the elevations of the optical elements, the transmissive layer having a first height in the cavities that is larger than the predetermined maximum height difference, and surfacing the transmissive layer after providing the transmissive layer such that the transmissive layer has a second height on the elevations that is substantially zero or larger, thereby providing a transmissive layer with a substantially planar surface.

Abstract: A lithographic projection apparatus for EUV lithography includes a foil trap, or channel barrier. The foil trap forms an open structure after the source to let the radiation pass unhindered. The foil trap is configured to be rotatable around an optical axis. By rotating the foil trap, an impulse transverse to the direction of propagation of the radiation can be transferred on debris present in the beam. This debris will not pass the foil trap. In this way, the amount of debris on the optical components downstream of the foil trap is reduced. The foil trap may be alternately rotated around the optical axis in a first direction and a second direction opposite the first direction.

Abstract: A radiation system includes a contamination barrier, e.g., a foil trap, between a collector, for example a normal incidence collector, and a radiation source, such that radiation coming from the source passes the foil trap twice. The radiation passes the contamination barrier once before hitting the collector and a second time after reflection by the collector. The foil trap includes lamellas that are parallel to both the radiation coming from the light source, and to the radiation reflected by the collector. The radiation is thus not obstructed by the foil trap. In this way, a normal incidence collector, which is used with a plasma produced source, can be protected from debris coming from a EUV source.

Abstract: A mirror has a mirror surface, wherein the mirror surface includes a protrusion including a material selected from at least one of Be, B, C, P, S, K, Ca, Sc, Br, Rb, Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pr, Pa and U, or a first protrusion including a first material selected from at least one of Be, B, C, P, S, K, Ca, Sc, Br, Rb, Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pr, Pa and U, and a second protrusion including a second material selected from at least one of Be, B, C, Si, P, S, K, Ca, Sc, Br, Rb, Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pr, Pa and U, and the first and second materials are not the same. A lithographic projection apparatus includes such a mirror. A device manufacturing method includes reflecting a beam of radiation by use of such a mirror. A device is manufactured according to the method.

Abstract: In a lithographic apparatus, a localized area of the substrate surface under a projection system is immersed in liquid. The height of a liquid supply system above the surface of the substrate can be varied using actuators. A control system uses feedforward or feedback control with input of the surface height of the substrate to maintain the liquid supply system at a predetermined height above the surface of the substrate.