Abstract: A radiation source for generating extreme ultraviolet radiation for a lithographic apparatus has a debris mitigation device comprising a nozzle arranged at or near an intermediate focus (IF) of the beam of radiation. The nozzle serves to direct a flow of gas (330) towards the radiation source or collector optic in order to deflect particulate debris (43) emitted by the radiation source.

Abstract: A multilayer mirror constructed to reflect radiation having a wavelength in the range of 6.4 nm to 7.2 nm. The multilayer mirror has alternating layers, including a first layer and a second layer. The first and second layers are selected from the group consisting of: U, or a compound or nitride thereof, and B4C layers; Th, or a compound or nitride thereof, and B4C layers; La, or a compound or nitride thereof, and B9C layers; La, or a compound or nitride thereof, and B4C layers; U, or a compound or nitride thereof, and B9C layers; Th, or a compound or nitride thereof, and B9C layers; La, or a compound or nitride thereof, and B layers; U, or a compound or nitride thereof, and B layers; C, or a compound or nitride thereof, and B layers; Th, or a compound or nitride thereof, and B layers.

Abstract: A spectral purity filter includes a body of material, through which a plurality of apertures extend. The apertures are arranged to suppress radiation having a first wavelength and to allow at least a portion of radiation having a second wavelength to be transmitted through the apertures. The second wavelength of radiation is shorter than the first wavelength of radiation. The body of material is formed from tungsten-molybdenum alloy or a molybdenum-rhenium alloy or a tungsten-rhenium alloy or a tungsten-molybdenum-rhenium alloy.

Abstract: A multilayer mirror is configured to reflect extreme ultraviolet (EUV) radiation while absorbing a second radiation having a wavelength substantially-longer than that of the EUV radiation. The mirror includes a plurality of layer pairs stacked on a substrate. Each layer pair comprises a first layer that includes a first material, and a second layer that includes a second material. The first layer is modified to reduce its contribution to reflection of the second radiation, compared with a simple layer of the same metal having the same thickness. Modifications can include doping with a third material in or around the metal layer to reduce its electric conductivity by chemical bonding or electron trapping, and/or splitting the metal layer into sub-layers with insulating layers. The number of layers in the stack is larger than known multilayer mirrors and may be tuned to achieve a minimum in IR reflection.

Abstract: A spectral purity filter, in particular for use in a lithographic apparatus using EUV radiation for the projection beam, includes a plurality of apertures in a substrate. The apertures are defined by walls having side surfaces that are inclined to the normal to a front surface of the substrate.

Abstract: A spectral purity filter includes a substrate, a plurality of apertures through the substrate, and a plurality of walls. The walls define the plurality of apertures through the substrate. The spectral purity filter also includes a first layer formed on the substrate to reflect radiation of a first wavelength, and a second layer formed on the first layer to prevent oxidation of the first layer. The apertures are constructed and arranged to be able to transmit at least a portion of radiation of a second wavelength therethrough.

Abstract: A lithographic apparatus includes an optical element that includes an oriented carbon nanotube sheet. The optical element has an element thickness in the range of about 20-500 nm and has a transmission for EUV radiation having a wavelength in the range of about 1-20 nm of at least about 20% under perpendicular irradiation with the EUV radiation.

Abstract: Embodiments of the invention relate to a mirror (30). The mirror includes a mirroring surface and a profiled coating layer (32a) having an outer surface, wherein one or more wedged elements are formed by the outer surface with respect to the mirroring surface, and wherein the one or more wedged elements having a wedge angle (ø) in a range of approximately 10-200 mrad. The profiled coating layer may have a curved outer surface. The profiled coating layer may be formed from at least one of the following materials: Be, B, C, P, K, Ca, Sc, Br, Rb, Sr, Y, Zr, Ru, Nb, Mo, Ba, La, Ce, Pr, Pa and U.

Abstract: An imprint lithography method is disclosed that includes, after imprinting an imprint lithography template into a layer of imprintable medium to form a pattern in that imprintable medium and fixing that pattern to form a patterned layer of imprintable medium, adding etch resistant material (i.e. a hard mask) to a part of the patterned layer of imprintable medium to reduce a difference between an intended topography and an actual topography of that part of the patterned layer of imprintable medium.

Abstract: A contaminant trap is used in an EUV radiation source apparatus. An EUV radiation beam is generated and focused through a low pressure gaseous atmosphere into a virtual source point. The EUV radiation creates a plasma in the low pressure hydrogen atmosphere through which it passes. A contaminant trap including electrodes is located in or around radiation beam as it approaches the virtual source point. A DC biasing source is connected to the electrodes to create an electric field oriented to deflect out of the beam path contaminant particles that have been negatively charged by the plasma. Additional RF electrodes and/or an ionizer enhance the plasma to increase the charging of the particles. The deflecting electrodes can be operated with RF bias for a short time, to ensure dissipation of the enhanced plasma.

Abstract: A spectral purity filter is configured to allow transmission therethrough of extreme ultraviolet (EUV) radiation and to refract or reflect non-EUV secondary radiation. The spectral purity filter may be part of a source module and/or a lithographic apparatus.

Abstract: A system and method are used to detect thermal radiation from a mask. Debris particles on the mask heat up, but do not cool down as quickly as the surrounding mask. Due to the temperature difference, the wavelength of radiation emitted by particles and the mask differs. Thus by detecting the thermal radiation, it is possible to detect the presence of particles deposited on the mask. If particles are detected, the mask can be cleaned.

Abstract: A radiation source is configured to generate extreme ultraviolet radiation. The radiation source includes a plasma formation site located at a position in which a fuel will be contacted by a beam of radiation to form a plasma, an outlet configured to allow gas to exit the radiation source, and a contamination trap at least partially located inside the outlet. The contamination trap is configured to trap debris particles that are generated with the formation of the plasma.

Abstract: A transmissive spectral purity filter is configured to transmit extreme ultraviolet radiation. The spectral purity filter includes a filter part having a plurality of apertures configured to transmit extreme ultraviolet radiation and to suppress transmission of a second type of radiation. Each aperture has been manufactured by an anisotropic etching process.

Abstract: A spectral purity filter is configured to transmit extreme ultraviolet (EUV) radiation and deflect or absorb non-EUV secondary radiation. In an embodiment, the spectral purity filter includes a body of material highly transmissive of EUV radiation and a layer of material highly reflective of non-EUV secondary radiation located on a radiation incident side of the body. In an embodiment, the spectral purity filter includes a body of material highly transmissive of EUV radiation and a layer of high emissivity material on an end of the body.

Abstract: A source module for use in a lithographic apparatus is constructed to generate extreme ultra violet (EUV) and secondary radiation, and includes a buffer gas configured to cooperate with a source of the EUV radiation. The buffer gas has at least 50% transmission for the EUV radiation and at least 70% absorption for the secondary radiation.

Abstract: A spectral purity filter includes a plurality of apertures extending through a member. The apertures are arranged to suppress radiation having a first wavelength and to allow at least a portion of radiation having a second wavelength to be transmitted through the apertures. The second wavelength of radiation is shorter than the first wavelength of radiation, A first region of the spectral purity filter has a first configuration that results in a first radiation transmission profile for the radiation having the first wavelength and the radiation having the second wavelength, and a second region of the spectral purity filter has a second, different configuration that results in a second, different radiation transmission profile for the radiation having the first wavelength and the radiation having the second wavelength.

Abstract: An optical element includes a first layer that includes a first material, and is configured to be substantially reflective for radiation of a first wavelength and substantially transparent for radiation of a second wavelength. The optical element includes a second layer that includes a second material, and is configured to be substantially absorptive or transparent for the radiation of the second wavelength. The optical element includes a third layer that includes a third material between the first layer and the second layer, and is substantially transparent for the radiation of the second wavelength and configured to reduce reflection of the radiation of the second wavelength from a top surface of the second layer facing the first layer. The first layer is located upstream in the optical path of incoming radiation with respect to the second layer in order to improve spectral purity of the radiation of the first wavelength.

Abstract: A radiation system includes a target material supply configured to supply droplets of target material along a trajectory, and a laser system that includes an amplifier and optics. The optics are configured to establish a first beam path which passes through the amplifier and through a first location on the trajectory, and to establish a second beam path which passes through the amplifier and through a second location on the trajectory. The laser system is configured to generate a first pulse of laser radiation when photons emitted from the amplifier are reflected along the first beam path by a droplet of target material at the first location on the trajectory. The laser system is configured to generate a second pulse of laser radiation when photons emitted from the amplifier are reflected along the second beam path by the droplet of target material at the second location on the trajectory.

Abstract: A transmissive spectral purity filter is configured to transmit extreme ultraviolet radiation. The spectral purity filter includes a filter part having a plurality of apertures to transmit extreme ultraviolet radiation and to suppress transmission of a second type of radiation. The apertures may be manufactured in carrier material such as silicon by an anisotropic etching process and topped with a reflective layer such as Mo metal, Ru metal, TiN or RuO. A diffusion barrier layer such as silicon nitride Si3N4, or silicon dioxide SiO2 is provided between the metal and the semiconductor to prevent diffusion and silicidation of the metal at elevated temperatures. The diffusion barrier layer may also serve as a hydrogen-resistant layer on parts of the semiconductor which are not beneath the reflective layer, and/or enhance emissivity for removal of heat from the structure.