Abstract: A lithographic apparatus includes a source configured to generate a radiation beam comprising desired radiation and undesired radiation using a plasma, an illumination system configured to condition the radiation beam and to receive hydrogen gas during operation of the lithographic apparatus, and a support structure constructed to hold a patterning device. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. A substrate table is constructed to hold a substrate, and a projection system is configured to project the patterned radiation beam onto a target portion of the substrate. The lithographic apparatus is configured such that the radiation beam on entering the projection system includes at least 50% of the undesired radiation that is generated by the plasma and includes wavelengths of radiation that interact with the hydrogen gas to generate hydrogen radicals.

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 radiation source is configured to generate radiation. The radiation source includes a first electrode and a second electrode configured to produce an electrical discharge during use to generate radiation-emitting plasma from a plasma fuel. The radiation source also includes a fuel supply configured to supply a plasma fuel to a fuel release area that is associated with the first electrode and the second electrode, and a fuel release configured to induce release of fuel, supplied by the fuel supply, from the fuel release area. The fuel release area is spaced-apart from the first electrode and from the second electrode.

Abstract: A lithographic apparatus comprising a support configured to support a patterning device; a substrate table configured to hold a substrate; a projection system configured to project a pattern imparted to a radiation beam by the patterning device onto a target portion of the substrate; and a first multi-layer mirror and a second multi-layer mirror, the first multi-layer mirror and the second multi-layer minor being arranged along a path of the radiation beam, the first multi-layer minor and the second multi-layer mirror each having a reflectivity of at least about 50% in extreme ultra violet wavelength range, and the first multi-layer mirror configured to reduce radiation having wavelengths in a first wavelength range and the second multi-layer minor configured to reduce radiation having wavelengths in a second wavelength range different from the first wavelength range, wherein the first wavelength range and the second wavelength range are outside extreme ultra violet wavelength range.

Abstract: A system for detecting at least one contamination species in an interior space of a lithographic apparatus, including: at least one monitoring surface configured to be in contact with the interior space, a thermal controller configured to control the temperature of the monitoring surface to at least one detection temperature, and at least one detector configured to detect condensation of the at least one contamination species onto the monitoring surface.

Abstract: A method for removal of a deposition on an uncapped multilayer mirror of an apparatus. The method includes providing a gas that includes one or more of H2, D2 and DH, and one or more additional compounds selected from hydrocarbon compounds and/or silane compounds in at least part of the apparatus; producing hydrogen and/or deuterium radicals and radicals of the one or more additional compounds, from the gas; and bringing the uncapped multilayer mirror with deposition into contact with at least part of the hydrogen and/or deuterium radicals and the radicals of the one or more additional compounds to remove at least part of the deposition.

Abstract: An optical apparatus includes an illumination system configured to form a pulsed radiation beam, an optical element with a surface on which the radiation beam is incident in operation, and a gas source arranged to supply a mixture of a first type of gas and a second type of gas to a space adjacent the surface. Particles of the first and second types of gas are capable of reacting with the surface, when activated by the radiation beam. The gas source is configured to generate a combination of surface occupation numbers of molecules of the first and second types of gas on the surface under operating conditions, at least prior to pulses of the radiation beam, the combination of surface occupation numbers lying in a range in which reactions of particles with the surface during pulses of the radiation beam are in majority reversed.

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 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.

Abstract: A multilayer mirror is constructed and arranged to reflect radiation haying a wavelength in the range of 2-8 nm. The multilayer mirror has alternating layers selected from the group consisting of: Cr and Sc layers, Cr and C layers, C and B4C layers, U and B4C layers, Th and B4C layers, C and B9C layers, La and B9C layers, U and B9C layers, Th and B9C layers, La and B layers, C and B layers. U and B layers, and Th and B layers.

Abstract: A method of determining an offset between an imprint template and a substrate using an alignment grating on the imprint template and an alignment grating on the substrate is disclosed. The method includes bringing the imprint template alignment grating and the substrate alignment grating sufficiently close together such that they form a composite grating, directing an alignment radiation beam at the composite grating while modulating the relative position of the imprint template and the substrate, detecting the intensity of alignment radiation which is reflected from the composite grating, and determining the offset by analyzing modulation of the detected intensity.

Abstract: In an embodiment, there is provided an imprint lithography method that includes providing a first amount of imprintable medium on a first area of a substrate, the first amount of imprintable medium, when fixed, having a first etch rate; and providing a second amount of imprintable medium on a second, different area of the substrate, the second amount of imprintable medium, when fixed, having a second, different etch rate.

Abstract: A system for detecting at least one contamination species in an interior space of a lithographic apparatus, including: at least one monitoring surface configured to be in contact with the interior space, a thermal controller configured to control the temperature of the monitoring surface to at least one detection temperature, and at least one detector configured to detect condensation of the at least one contamination species onto the monitoring surface.

Abstract: A spectral purity filter includes a plurality of apertures extending through a member. The apertures are arranged to suppress a first wavelength of radiation and to allow at least a portion of a second wavelength of radiation to be transmitted through the apertures. The second wavelength of radiation is shorter than the first wavelength of radiation. The apertures extend though the member in different directions in order to be substantially in alignment with radiation constituting a non-parallel beam of radiation.

Abstract: A target material is configured to be used in a source constructed and arranged to generate a radiation beam having a wavelength in an extreme ultraviolet range. The target material includes a Gd-based composition configured to modify a melting temperature of Gd.

Abstract: In an aspect, an inspection method for detecting the presence or absence of a defect on an object, the object comprising a recess having a physical depth, is disclosed. The method includes directing radiation at the object, the radiation having a wavelength that is substantially equal to twice an optical depth of the recess, detecting radiation that is re-directed by the object or a defect on the object, and determining the presence or absence of a defect from the re-directed 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: 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 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 radiation source is constructed and arranged to produce extreme ultraviolet radiation. The radiation source includes a chamber, a first electrode at least partially contained in the chamber, a second electrode at least partially contained in the chamber, and a supply constructed and arranged to provide a discharge gas to the chamber. The first electrode and the second electrode are configured to create a discharge in the discharge gas to form a plasma so as to generate the extreme ultraviolet radiation. The source also includes a gas supply constructed and arranged to provide a gas at a partial pressure between about 1 Pa and about 10 Pa at a location near the discharge. The gas is selected from the group consisting of hydrogen, helium, and a mixture of hydrogen and helium.