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: 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: 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: 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: 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: 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.

Abstract: In a lithographic apparatus, an illumination mode is set using a field mirror that includes a plurality of movable facets to direct radiation to selectable positions on a pupil facet mirror. A base illumination mode is selected from a set of predetermined illumination modes and the movable facets are set to effect that mode. In order to adjust an imaging parameter, a fraction of the movable facets are set to different positions. The determination of which facets to set to different positions is based on summing the effects of setting each facet to a different position.

Abstract: An illumination system is disclosed that had a plurality of moveable reflective elements and associated actuators which may be configured to form an illumination mode. One or more of the actuators is arranged to move between first, second and third positions, and so move an associated moveable reflective element between first, second and third orientations, the first and second orientations being such that radiation reflected from the moveable reflective element forms part of the illumination mode, and the third orientation being such that radiation reflected from the moveable reflective element does not form part of the illumination mode.

Abstract: An optical apparatus has a moveable reflective element and associated actuator. The actuator includes a first magnet which is connected to the moveable reflective element such that movement of the first magnet will cause the moveable reflective element to move, and a second magnet which is connected to a motor such that operation of the motor will cause the second magnet to move. The second magnet is positioned relative to the first magnet such that moving the second magnet will cause the first magnet to move.

Abstract: An array of reflective elements in which at least one of the reflective elements is mounted on a mounting which comprises a rod at least partially located within a sleeve. A first end of the rod is fixed to a first end of the sleeve and a second end of the rod is moveable, the sleeve including a first resiliently flexible portion which is configured to bend in order to allow the movement of the second end of the rod to take place, wherein the reflective element is mounted at the first end of the sleeve such that bending of the sleeve causes rotation of the reflective element.

Abstract: A lithographic apparatus includes an illumination system configured to condition a radiation beam and a support constructed to support a patterning device. The patterning device is configured 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 apparatus includes a heater arrangement that includes an electron beam generator configured to generate an electron beam, and an electron beam guide arrangement configured to guide the electron beam onto an optical element of the lithographic apparatus. The optical element forms a part of the illumination system or the projection system which, in use, is traversed by the radiation beam. The heater arrangement is controllable to provide a distribution of heat on the optical element by deflection of the electron beam.

Abstract: An actuator system is provided that is configured to move a component relative to a base of the actuator system. The actuator system may include first and second actuating elements, each including two sections of material that are joined to each other and have different coefficients of thermal expansion. The two actuating elements may be configured such that if the temperature of one is increased it applies a force on the component in a direction that is opposite to the force applied by the other actuating element if its temperature is increased. The actuator system may further include at least one power supply configured to provide independently controllable heating to the first and second actuating elements.

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.