Abstract: A radiation source for generating EUV radiation includes a laser configured to fire laser pulses at a target area to which is supplied a stream of fuel droplets, which may be tin droplets that emit EUV radiation when excited by the laser beam. The EUV radiation is collected by a collector. The tin droplets may be pre-conditioned by a laser pre-pulse before the main laser pulse to change the shape of the droplets so that the droplets are in an optimum condition for receiving the main laser pulse. Embodiments of the invention take into account the effect of the vaporization of one fuel droplet on succeeding droplets and allow the timing of the main and/or pre-pulse to be adjusted to take into account any delay in arrival of the subsequent droplet or oscillations in the shape of the subsequent droplet which may be caused by vaporization of the preceding droplet.

Abstract: According to an aspect of the present invention, a spectral purity filter includes an aperture, the aperture being arranged to diffract a first wavelength of radiation and to allow at least a portion of a second wavelength of radiation to be transmitted through the aperture, the second wavelength of radiation being shorter than the first wavelength of radiation, wherein the aperture has a diameter greater than 20 ?m.

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 source-collector device is constructed and arranged to generate a radiation beam, The device includes a target unit constructed and arranged to present a target surface of plasma-forming material; a laser unit constructed and arranged to generate a beam of radiation directed onto the target surface so as to form a plasma from said plasma-forming material; a contaminant trap constructed and arranged to reduce propagation of particulate contaminants generated by the plasma; a radiation collector comprising a plurality of grazing-incidence reflectors arranged to collect radiation emitted by the plasma and form a beam therefrom; and a filter constructed and arranged to attenuate at least one wavelength range of the beam.

Abstract: A radiation source (60) suitable for providing a beam of radiation to an illuminator of a lithographic apparatus. The radiation source comprises a nozzle configured to direct a stream of fuel droplets (62) along a trajectory (64) towards a plasma formation location (66). The radiation source is configured to receive a first amount of radiation (68) such that the first amount of radiation is incident on a fuel droplet (62a) at the plasma formation location, and such that the first amount of radiation transfers energy into the fuel droplet to generate a modified fuel distribution (70), the modified fuel distribution having a surface.

Abstract: A radiation source having a fuel stream generator (110) that generates and directs a fuel stream (102) along a trajectory towards a plasma formation location (104). A pre-pulse laser radiation assembly directs a first beam of laser radiation (100) at the fuel stream at the plasma formation location to generate a modified fuel target (106). A main pulse laser radiation assembly directs a second beam of laser radiation (108) at the modified fuel target at the plasma formation location to generate a radiation generating plasma (117). A collector (122) collects the radiation and directs it along an optical axis (105) of the radiation source. The first beam of laser radiation being directed toward the fuel stream substantially along the optical axis.

Abstract: A lithographic process includes the use of a silicon-containing polymer or a compound that includes at least one element selected from the group consisting of: Ta, W, Re, Os, Ir, Ni, Cu or Zn in a resist material for an EUV lithographic process. The wavelength of the EUV light used in the process is less than 11 nm, for example 6.5-6.9 nm. The invention further relates to novel silicon-containing polymers.

Abstract: A multilayer mirror for use in device lithography is configured to reflect and/or pattern radiation having a wavelength in the range of about 6.4 nm to about 7.2 nm. The multilayer mirror has a plurality of alternating layers of materials. The plurality of alternating layers of materials include first layers of materials and second layers of materials. The second layers have a higher refractive index for the radiation than the first layers. The materials of the first layers and the materials of the second layers are mutually chemically unreactive at an interface therebetween at temperatures less than 300° C. This may allow the mirrors to have a narrow boundary region of intermingled materials from alternating layers between the layers, for example of 0.5 nm or less in width, which may improve sharpness of the boundary region and improve reflectivity.

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 pellicle that includes graphene is constructed and arranged for an EUV reticle. A multilayer mirror includes graphene as an outermost layer.

Abstract: A lithographic apparatus for patterning a beam of radiation and projecting it onto a substrate, comprising at least two spectral purity filters configured to reduce the intensity of radiation in the beam of radiation in at least one undesirable range of radiation wavelength, wherein the two spectral purity filters are provided with different radiation filtering structures from each other.

Abstract: A grazing incidence reflector (300) for EUV radiation includes a first mirror layer (310) and a multilayer mirror structure (320) beneath the first mirror layer. The first mirror layer reflects at least partially EUV radiation incident on the reflector with grazing incidence angles in a first range, and the first mirror layer transmits EUV radiation in a second range of incidence angles, which overlaps and extends beyond the first range of incidence angles. The multilayer mirror structure reflects EUV radiation that is incident on the reflector with grazing incidence angles in a second range that penetrates through the first mirror layer. A grazing incidence reflector can be used in a lithographic apparatus and in manufacturing a device by a lithographic process.

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 lithographic apparatus includes a radiation source configured to produce a radiation beam, and a support configured to support a patterning device. The patterning device is configured to impart the radiation beam with a pattern to form a patterned radiation beam. A chamber is located between the radiation source and patterning device. The chamber contains at least one optical component configured to reflect the radiation beam, and is configured to permit radiation from the radiation source to pass therethrough. A membrane is configured to permit the passage of the radiation beam, and to prevent the passage of contamination particles through the membrane. A particle trapping structure is configured to permit gas to flow along an indirect path from inside the chamber to outside the chamber. The indirect path is configured to substantially prevent the passage of contamination particles from inside the chamber to outside the chamber.

Abstract: EUV exposure dose in a lithographic apparatus is controlled pulse to pulse by varying a conversion efficiency with which a pulse of EUV radiation is generated from an excitation of a fuel material by a corresponding pulse of excitation laser radiation. Conversion efficiency can be varied in several different ways, by varying the proportion of a fuel material that intersects a laser beam, and/or by varying a quality of the interaction. Mechanisms to vary the conversion efficiency can be based on variation of a laser pulse timing, variation of pre-pulse energy, and/or variable displacement of a main laser beam in one or more directions. Steps to maintain symmetry of the generated EUV radiation can be included.

Abstract: A system for removing contaminant particles from the path of the beam of EUV radiation is provided in which at least a first AC voltage is provided to a pair of electrodes on opposite sides of the path of the beam of EUV radiation as a first stage of a regime of voltages and, as a second stage of the regime of voltages, a DC voltage is provided to the electrodes.

Abstract: There is provided a multilayer mirror (80) comprising a layer of a first material (84) and a layer of silicon (82). The layer of the first material and the layer of silicon form a stack of layers. An exposed region of the layer of silicon comprises a modification that is arranged to improve the robustness of the exposed region of silicon.

Abstract: According to an aspect of the present invention, a spectral purity filter includes an aperture, the aperture being arranged to diffract a first wavelength of radiation and to allow at least a portion of a second wavelength of radiation to be transmitted through the aperture, the second wavelength of radiation being shorter than the first wavelength of radiation, wherein the aperture has a diameter greater than 20 ?m.

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 a material having a bulk reflectance of substantially greater than or equal to 70% at the first wavelength of radiation. The material has a melting point above 1000° C.

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.