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: An EUV illumination system, for example, for use in a photolithographic apparatus is configured to condition a radiation beam. A hydrogen radical source configured to supply gas containing hydrogen or hydrogen radicals into the illumination system. The hydrogen gas is effective to remove carbonaceous contamination from the surface of a mirror in the illumination system or to form a buffer against unwanted gases. In order to prevent damage by hydrogen that penetrates the mirror, the mirror comprises a layer made of metal non-metal compound adjacent a reflection surface of the mirror. A transition metal carbide, nitride, boride or silicide compound or mixture thereof may be used for example.

Abstract: An apparatus for forming a beam of electromagnetic radiation. The apparatus includes a plasma radiation source, a foil trap provided with a plurality of thin foils that extend substantially parallel to the direction of radiation from the plasma source, and a grid disposed between the plasma radiation source and the foil trap. A space is located between the grid and the foil trap. An electrical potential application circuit is constructed and arranged to apply an electrical potential to the grid so that the grid repels electrons emitted by the plasma radiation source and creates a positive space charge between the grid and the foil trap to deflect ions emitted by the plasma radiation source to the foil trap. A distance between the grid and the foil trap is at least equal to one-half of a radius of the foil trap.

Abstract: A source configured to generate radiation for a lithographic apparatus is disclosed. The source includes an anode, and a cathode. The cathode and the anode are configured to create a discharge in a fuel in a discharge space between the anode and the cathode so as to generate a plasma, the cathode and the anode positioned relative to each other so that, in use, current lines extending between the anode and the cathode are substantially curved so as to create a force that substantially radially compresses the plasma only in a region proximate an upper surface of the cathode or of the anode.

Abstract: An imprint lithography apparatus is disclosed that includes a structure located away from a substrate holder and extending across the substrate holder, and such that an imprint template arrangement is, in use, located between the structure and the substrate holder, wherein the structure has one or more arrays of lines or one or more encoders, and the substrate or substrate holder and the imprint template have a corresponding one or more encoders that face towards one or more of the one or more arrays of lines or one or more arrays of lines that face towards one or more of the one or more encoders, and the configuration determination arrangement is configured to determine a relative configuration between the substrate or substrate holder and the structure, and/or a relative configuration between the imprint template arrangement and the structure, and/or a relative configuration between the imprint template arrangement and the substrate or substrate holder.

Abstract: A method for removal of deposition on a radiation collector of a lithographic apparatus includes providing a gas barrier to an end of a radiation collector, thereby providing a radiation collector enclosure volume; providing a gas to the enclosure volume, the gas selected from a halogen containing gas and a hydrogen containing gas; and removing at least part of the deposition from the radiation collector. A lithographic apparatus includes a radiation collector; a circumferential hull enclosing the radiation collector; a gas barrier at an end of the radiation collector, thereby providing a radiation collector enclosure volume. The radiation collector is enclosed by the circumferential hull and the gas barrier. An inlet provides a gas to the radiation collector enclosure volume and an outlet removes a gas from the radiation collector enclosure volume.

Abstract: An imprint lithography apparatus is disclosed that includes an imprint template holder arranged to hold an imprint template, and a plurality of position sensors configured to measure change of the size and/or shape of the imprint template, wherein the position sensors are mechanically isolated from the imprint template. Also disclosed is a lithography method that includes using an imprint template to imprint a pattern onto a substrate, and measuring changes of the size and/or shape of the imprint template while imprinting the pattern onto the substrate.

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: A patterned beam of radiation is projected onto a substrate. A reflective optical element is used to help form the radiation beam from radiation emitted from a plasma region of a plasma source. In the plasma source, a plasma current is generated in the plasma region. To reduce damage to the reflective optical element, a magnetic field is applied in the plasma region with at least a component directed along a direction of the plasma current. This axial magnetic field helps limit the collapse of the Z-pinch region of the plasma. By limiting the collapse, the number of fast ions emitted may be reduced.

Abstract: A collector assembly with a radiation collector, a cover plate and a support member connecting the radiation collector to the cover plate are provided. The cover plate is designed to cover an opening in a collector chamber. The collector chamber opening may be large enough to pass the radiation collector and the support member. The removed radiation collector can be cleaned with different cleaning procedures, which may be performed in a cleaning device. Such cleaning device may for example consist of the following: a circumferential hull designed to provide an enclosure volume for circumferentially enclosing at least the radiation collector; an inlet configured to provide at least one of a cleaning gas and a cleaning liquid to the enclosure volume to clean at least said radiation collector; and an outlet configured to remove said at least one of said cleaning gas and said cleaning liquid from the enclosure volume.

Abstract: An apparatus for forming a beam of electromagnetic radiation includes a plasma radiation source, and a foil trap provided with a plurality of thin foils that extend substantially parallel to the direction of radiation from the plasma source. A grid is disposed between the plasma radiation source and the foil trap. A space is located between the grid and the foil trap. The apparatus also include an electrical potential application circuit that is constructed and arranged to apply an electrical potential to the grid so that the grid repels electrons emitted by the plasma radiation source and creates a positive space charge between the grid and the foil trap to deflect ions emitted by the plasma radiation source to the foil trap.

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 contaminant trap apparatus arranged in a path of a radiation beam to trap contaminants emanating from a radiation source configured to produce the radiation beam is disclosed. The contaminant trap apparatus includes a rotor having a plurality of channel forming elements defining channels which are arranged substantially parallel to the direction of propagation of the radiation beam, the rotor including electrically chargeable material and arranged to be electrically charged as a result of the operation of the radiation source; and a bearing configured to rotatably hold the rotor with respect to a rotor carrying structure, wherein the apparatus is configured to (i) control or redirect an electrical discharge of the rotor, or (ii) suppress an electrical discharge of the rotor, or (iii) both (i) and (ii).

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 source includes a chamber, a supply constructed and arranged to supply a substance to the chamber at a location that allows the substance to pass through an interaction point within the chamber, a laser constructed and arranged to provide a laser beam to the interaction point so that a radiation emitting plasma is produced when the laser beam interacts with he substance at the interaction point, and a conduit constructed and arranged to deliver unheated buffer gas into the chamber at a location adjacent to the interaction point at a rate that removes heated buffer gas from a region around the interaction point before a subsequent interaction between the laser beam and the substance at the interaction point.

Abstract: An assembly for detection of at least one of radiation flux and contamination on an optical component includes a detector configured to receive at least one of the radiation flux and contamination, and when the assembly is in use, to generate a detector signal correlated to at least one of the radiation flux and contamination on the component. A meter is configured to measure the detector signal. The detector includes at least one wire.

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: An assembly is provided for blocking a beam of radiation. The assembly has a pipe arranged to transmit at least part of the beam of radiation. The pipe has an inner surface provided with an ablation material and encloses a volume. The assembly further has an ablation generation device. The ablation generation device is arranged to ablate at least a portion of the ablation material upon reception of a blocking signal. The assembly has a control unit, which is arranged to control the ablation generation device.

Abstract: A collector assembly with a radiation collector, a cover plate and a support member connecting the radiation collector to the cover plate are provided. The cover plate is designed to cover an opening in a collector chamber. The collector chamber opening may be large enough to pass the radiation collector and the support member. The removed radiation collector can be cleaned with different cleaning procedures, which may be performed in a cleaning device. Such cleaning device may for example consist of the following: a circumferential hull designed to provide an enclosure volume for circumferentially enclosing at least the radiation collector; an inlet configured to provide at least one of a cleaning gas and a cleaning liquid to the enclosure volume to clean at least said radiation collector; and an outlet configured to remove said at least one of said cleaning gas and said cleaning liquid from the enclosure volume.