Abstract: A device is constructed and arranged to generate radiation by using an electrical discharge through a gaseous medium. The device includes a first electrode and a second electrode, and a liquid supply arranged to provide a liquid to a location in the device. The device is arranged to be electrically supplied with a voltage and to supply the voltage at least partially to the first electrode and the second electrode in order to allow the electrical discharge to be generated in an electrical field created by the voltage. The electrical discharge produces a radiating plasma. The device also includes a shield arranged between the discharge location and a conducting part connected to the first electrode and/or the second electrode.

Abstract: A lithographic apparatus includes a plasma source that includes a vessel configured to enclose a plasma formation site, an optical device configured to transfer optical radiation to or from the vessel, and a reflector arranged in an optical path between the optical device and the plasma formation site source. The reflector is configured to reflect the optical radiation between the optical device and the plasma formation site. The reflector is formed, in operation, as a molten metal mirror.

Abstract: An optical sensor apparatus for use in an extreme ultraviolet lithographic system is disclosed. The apparatus includes an optical sensor comprising a sensor surface and a removal mechanism configured to remove debris from the sensor surface. Accordingly, dose and/or contamination measurements may be carried out conveniently for the lithographic system.

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.

Abstract: An assembly including a radiation reflector and a contaminant barrier is disclosed. The contaminant barrier is arranged to receive radiation from a radiation source and to reflect that radiation towards the radiation reflector, and the radiation reflector is arranged to reflect the radiation, received from the contaminant barrier, back towards the contaminant barrier.

Abstract: A collector assembly for use in a laser-produced plasma extreme ultraviolet radiation source for use in lithography has a collector body having a collector mirror and a window in the collector body. The window is transmissive to excitation radiation, which may be an infrared laser beam, so that it can pass through the window to excite the plasma, and the window has an EUV minor on its surface which is also transmissive to the excitation beam but which can reflect EUV generated by the plasma to the collector location of the collector mirror. The window may improve the collection efficiency and reduce non-uniformity in the image at the collector location. Radiation sources, lithographic apparatus and device manufacturing methods may make use of the collector.

Abstract: A lithographic spectral filter including a first filter element including a slit having an in plane length dimension arranged in a first direction; and a second filter element arranged at a subsequent position along an optical path of radiation of first and second wavelengths to the first filter element, the second filter element including a slit having an in plane length dimension arranged in a second direction transverse to the first direction, wherein the spectral filter is configured to reflect radiation of a first wavelength and allow transmission of radiation of a second wavelength, the first wavelength being larger than the second wavelength.

Abstract: A patterning device for a photolithographic apparatus is used to form a patterned radiation beam, by imparting a cross-sectional pattern to the radiation beam during reflection from the patterning device. The patterning device comprises a layer of phase-change material that is capable of locally undergoing an induced structural phase change into respective ones of a plurality of stable and/or metastable states. Furthermore, the patterning device comprises a radiation reflective structure with periodically arranged layers adjacent to the layer of phase-change material. The radiation reflective structures do not partake in the phase changes. By locally changing the phase of the phase-change material, the reflectivity of the whole structure is modified, for example due to thickness changes in the layer of phase-change material that lead to destructive interference of different components of the reflected light or due to changes in surface roughness of the radiation reflective structure.

Abstract: A radiation source having self-shading electrodes is disclosed. Debris originating from the electrodes is reduced. The path from the electrodes to the EUV optics is blocked by part of the electrodes themselves (termed self-shading). This may significantly reduce the amount of electrode-generated debris.

Abstract: A radiation source having self-shading electrodes is disclosed. Debris originating from the electrodes is reduced. The path from the electrodes to the EUV optics is blocked by part of the electrodes themselves (termed self-shading). This may significantly reduce the amount of electrode-generated debris.

Abstract: A debris mitigation system for trapping debris coming from a tin debris-generating radiation source is provided. The debris mitigating system includes a debris barrier comprising a plurality of foils, and a cleaning system constructed and arranged to clean the foils. The cleaning system includes a supply unit to provide a liquid alloy to the foils to dissolve and flush trapped debris from the foils. The alloy includes gallium, indium, tin, or any combination thereof.

Abstract: A radiation system for generating a beam of radiation that defines an optical axis is provided. The radiation system includes a plasma produced discharge source for generating EUV radiation. The discharge source includes a pair of electrodes constructed and arranged to be provided with a voltage difference, and a system for producing a plasma between the pair of electrodes so as to provide a discharge in the plasma between the electrodes. The radiation system also includes a debris catching shield for catching debris from the electrodes. The debris catching shield is constructed and arranged to shield the electrodes from a line of sight provided in a predetermined spherical angle relative the optical axis, and to provide an aperture to a central area between the electrodes in the line of sight.

Abstract: A device is arranged to measure a quantity relating to radiation. The device includes a sensor configured to measure the quantity, a screen arranged to protect the sensor from incoming particles emitted from a source configured to emit extreme ultraviolet radiation, and a mirror configured to redirect extreme ultraviolet radiation emitted by the source, past the screen, to the sensor.

Abstract: A radiation system for generating a beam of radiation that defines an optical axis is provided. The radiation system includes a plasma produced discharge source for generating EUV radiation. The discharge source includes a pair of electrodes constructed and arranged to be provided with a voltage difference, and a system for producing a plasma between the pair of electrodes so as to provide a discharge in the plasma between the electrodes. The radiation system also includes a debris catching shield for catching debris from the electrodes. The debris catching shield is constructed and arranged to shield the electrodes from a line of sight provided in a predetermined spherical angle relative the optical axis, and to provide an aperture to a central area between the electrodes in the line of sight.

Abstract: A debris prevention system is constructed and arranged to prevent debris that emanates from a radiation source from propagating with radiation from the radiation source into or within a lithographic apparatus. The debris prevention system includes an aperture that defines a maximum emission angle of the radiation coming from the radiation source, and a first debris barrier having a radiation transmittance. The first debris barrier includes a rotatable foil trap. The debris prevention system also includes a second debris barrier that has a radiation transmittance. The first debris barrier is configured to cover a part of the emission angle and the second debris barrier is configured to cover another part of the emission angle.

Abstract: A lithographic apparatus includes a radiation source configured to produce extreme ultraviolet radiation. The source includes a chamber in which a plasma is generated, and a mirror configured to reflect radiation emitted by the plasma. The mirror includes a multi-layer structure that includes alternating Mo/Si layers. A boundary Mo layer or a boundary Si layer or a boundary diffusion barrier layer of the alternating layers forms a top layer of the mirror, the top layer facing inwardly with respect to the chamber. A hydrogen radical generator is configured to generate hydrogen radicals in the chamber. The radicals are configured to remove debris generated by the plasma from the mirror. A support is constructed and arranged to support a patterning device configured to pattern the radiation to form a patterned beam of radiation. A projection system is constructed and arranged to project the patterned beam of radiation onto a substrate.

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: Spectral purity of a radiation beam of a first wavelength may be improved by providing an optical element that includes a structure having at least first layer including a first material, which structure is configured to be substantially reflective for a radiation of the first wavelength and substantially transparent or absorptive for a radiation of a second wavelength, a second layer including a second material, the second layer being configured to be substantially reflective, absorptive or scattering for the radiation of the second wavelength, and vacuum between the first layer and the second layer, wherein the first layer is located upstream in the optical path of incoming radiation with respect to the second layer.

Abstract: An optical sensor apparatus for use in an extreme ultraviolet lithographic system is disclosed. The apparatus includes an optical sensor comprising a sensor surface and a removal mechanism configured to remove debris from the sensor surface. Accordingly, dose and/or contamination measurements may be carried out conveniently for the lithographic system.

Abstract: A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.