Abstract: A radiation system includes a beam splitting apparatus configured to split a main radiation beam into a plurality of branch radiation beams and a radiation alteration device arranged to receive an input radiation beam and output a modified radiation beam, wherein the radiation alteration device is configured to provide an output modified radiation beam which has an increased etendue, when compared to the received input radiation beam, wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a main radiation beam and the radiation alteration device is configured to provide a modified main radiation beam to the beam splitting apparatus, or wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a branch radiation beam output from the beam splitting apparatus.

Abstract: A lithographic apparatus arranged to project a pattern from a patterning device onto a substrate, comprising at least one housing comprising at least one internal wall, at least one optical component arranged within at least one chamber defined at least in part by the at least one internal wall and configured to receive a radiation beam and a cooling apparatus arranged to cool at least a portion of the at least one internal wall to a temperature below that of the at least one optical component.

Abstract: A beam-splitting apparatus arranged to receive an input radiation beam and split the input radiation beam into a plurality of output radiation beams. The beam-splitting apparatus comprising a plurality of reflective diffraction gratings arranged to receive a radiation beam and configured to form a diffraction pattern comprising a plurality of diffraction orders, at least some of the reflective diffraction gratings being arranged to receive a 0th diffraction order formed at another of the reflective diffraction gratings. The reflective diffraction gratings are arranged such that the optical path of each output radiation beam includes no more than one instance of a diffraction order which is not a 0th diffraction order.

Abstract: A lithographic apparatus comprising a projection system configured to project a patterned radiation beam to form an exposure area on a substrate held on a substrate table, the lithographic apparatus further comprising a cooling apparatus for cooling the substrate, wherein the cooling apparatus comprises a cooling element located above the substrate table and adjacent to the exposure area, the cooling element being configured to remove heat from the substrate.

Abstract: A radiation system includes a beam splitting apparatus configured to split a main radiation beam into a plurality of branch radiation beams and a radiation alteration device arranged to receive an input radiation beam and output a modified radiation beam, wherein the radiation alteration device is configured to provide an output modified radiation beam which has an increased etendue, when compared to the received input radiation beam, wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a main radiation beam and the radiation alteration device is configured to provide a modified main radiation beam to the beam splitting apparatus, or wherein the radiation alteration device is arranged such that the input radiation beam which is received by the radiation alteration device is a branch radiation beam output from the beam splitting apparatus.

Abstract: A radiation alteration device includes a continuously undulating reflective surface, wherein the shape of the continuously undulating reflective surface follows a substantially periodic pattern.

Abstract: A delivery system for use within a lithographic system. The beam delivery system comprises optical elements arranged to receive a radiation beam from a radiation source and to reflect portions of radiation along one or more directions to form a one or more branch radiation beams for provision to one or more tools.

Abstract: An apparatus (60) for adjusting an intensity of radiation. The apparatus comprises a grating (61) for receiving a radiation beam (Ba) and for directing at least a portion of the radiation beam in a first direction in the form of a first reflected radiation beam (Ba0), and one or more first actuators operable to rotate the grating to adjust a grazing angle between the radiation beam and a surface of the grating so as to vary an intensity of the reflected radiation beam.

Abstract: A reflector (2) comprising a plate (4) supported by a substrate (8), wherein the plate has a reflective surface (5) and is secured to the substrate by adhesive free bonding, and wherein a cooling channel array (10) is provided in the reflector. The channels (16) of the cooling channel array may be formed from open channels in a surface of the substrate, the open channels being closed by the plate to create the channels.

Abstract: A photocathode comprises a substrate in which a cavity is formed and a film of material disposed on the substrate. The film of material comprises an electron emitting surface configured to emit electrons when illuminated by a beam of radiation. The electron emitting surface is on an opposite side of the film of material from the cavity.

Abstract: A method of patterning lithographic substrates that includes using a free electron laser to generate EUV radiation and delivering the EUV radiation to a lithographic apparatus which projects the EUV radiation onto lithographic substrates. The method further includes reducing fluctuations in the power of EUV radiation delivered to the lithographic substrates by using a feedback-based control loop to monitor the free electron laser and adjust operation of the free electron laser accordingly, and applying variable attenuation to EUV radiation that has been output by the free electron laser in order to further control the power of EUV radiation delivered to the lithographic apparatus.

Abstract: An actuator to displace, for example a mirror, provides movement with at least two degrees of freedom by varying the currents in two electromagnets. A moving part includes a permanent magnet with a magnetic face constrained to move over a working area lying substantially in a first plane perpendicular to a direction of magnetization of the magnet. The electromagnets have pole faces lying substantially in a second plane closely parallel to the first plane, each pole face substantially filling a quadrant of the area traversed by the face of the moving magnet. An optical position sensor may direct a beam of radiation at the moving magnet through a central space between the electromagnets. The sizes of facets in a pupil mirror device may be made smaller in a peripheral region, but larger in a central region, thereby relaxing focusing requirements.

Abstract: A photocathode comprises a substrate in which a cavity is formed and a film of material disposed on the substrate. The film of material comprises an electron emitting surface configured to emit electrons when illuminated by a beam of radiation. The electron emitting surface is on an opposite side of the film of material from the cavity.

Abstract: An injector arrangement for providing an electron beam. The injector arrangement comprises a first injector for providing electron bunches, and a second injector for providing electrons bunches. The injector arrangement is operable in a first mode in which the electron beam comprises electron bunches provided by the first injector only and a second mode in which the electron beam comprises electron bunches provided by the second injector only.

Abstract: An EUV optical apparatus includes a number of adjustable mirrors (22x) on mirror bodies (120). Each mirror body is supported on an actuator (100x) comprising a moving part (132, 134, 136) and a fixed casing part (128, 130). The actuator provides a resilient support (140, 142) for the mirror body so that it is tiltable with two degrees relative to the casing. An electromagnetic motor (166, 170-178) applies first part, under the influence of an applied motive force, the resilient mounting being arranged to provide a biasing force that resists said motive force. A magnetic coupling (102, 104a, 104b) is arranged between the moving and fixed parts so as to provide a counter-biasing force. The counter-biasing force partly opposes said biasing force and thereby reduces the motive force required to effect a given displacement. The actuator can thus be made with reduced size, weight and heat dissipation.

Abstract: In an EUV (extreme ultraviolet) lithography apparatus, an illumination system includes a multifaceted field mirror and a multifaceted pupil mirror. A field facet mirror within mirror focuses EUV radiation onto a particular associated pupil facet mirror, from where it is directed to a target area. Each field facet mirror is modified to scatter unwanted DUV (deep ultraviolet) radiation into a range of directions. The majority of DUV falls onto neighboring pupil facet mirrors within the pupil mirrors, so that the amount of DUV radiation reaching target E is suppressed in comparison to the wanted EUV radiation. Because the distance between mirrors is much greater than the width of an individual pupil facet mirror, good DUV suppression can be achieved with only a narrow scattering angle. Absorption of EUV radiation in the scattering layer can be minimized.

Abstract: In a lithographic apparatus, an illumination mode is set using a field mirror comprising a plurality of movable facets to direct radiation to selectable positions on a pupil facet mirror. In the event that a field facet mirror is defective and cannot be set to a desired position, another of the movable facet mirrors is set to a corrective position, different than its desired position, to at least partially ameliorate a deleterious effect of the defective facet mirror.

Abstract: An actuator to displace, for example a mirror, provides movement with at least two degrees of freedom by varying the currents in two electromagnets. A moving part includes a permanent magnet with a magnetic face constrained to move over a working area lying substantially in a first plane perpendicular to a direction of magnetization of the magnet. The electromagnets have pole faces lying substantially in a second plane closely parallel to the first plane, each pole face substantially filling a quadrant of the area traversed by the face of the moving magnet. An optical position sensor may direct a beam of radiation at the moving magnet through a central space between the electromagnets. The sizes of facets in a pupil mirror device may be made smaller in a peripheral region, but larger in a central region, thereby relaxing focusing requirements.

Abstract: An EUV optical apparatus includes a number of adjustable mirrors (22x) on mirror bodies (120). Each mirror body is supported on an actuator (100x) comprising a moving part (132, 134, 136) and a fixed casing part (128, 130). The actuator provides a resilient support (140, 142) for the mirror body so that it is tiltable with two degrees relative to the casing. An electromagnetic motor (166, 170-178) applies first part, under the influence of an applied motive force, the resilient mounting being arranged to provide a biasing force that resists said motive force. A magnetic coupling (102, 104a, 104b) is arranged between the moving and fixed parts so as to provide a counter-biasing force. The counter-biasing force partly opposes said biasing force and thereby reduces the motive force required to effect a given displacement. The actuator can thus be made with reduced size, weight and heat dissipation.

Abstract: An illumination system of a lithographic apparatus includes a plurality of reflective elements arranged to receive radiation from a radiation source, the reflective elements being movable between different orientations. In the different orientations, the reflective elements direct radiation towards different locations at a reflective component in a pupil plane of the illumination system, thereby forming different illumination modes. Each reflective element is moveable between a first orientation, which directs radiation towards a first location the pupil plane, and a second orientation, which directs radiation towards a second location in the pupil plane. The first orientation and the second orientation of the reflective element are defined by end stops.