Abstract: Degradation of the reflectivity of one or more reflective optical elements in a system for generating EUV radiation is reduced by the controlled introduction of a gas into a vacuum chamber containing the optical element. The gas may be added to the flow of another gas such as hydrogen or alternated with the introduction of hydrogen radicals.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: A vessel (16) for an EUV radiation source, the vessel comprising a first opening (30) for accessing an interior (32) of the vessel, a first access member (34) configured to allow or prevent access to the interior of the vessel through the first opening, a second opening (36) for accessing the interior of the vessel, the second opening being arranged in the first access member and a second access member (38) arranged on the first access member and configured to allow or prevent access to the interior of the vessel through the second opening.

Abstract: A metrology system includes a light beam metrology apparatus configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects; a target metrology apparatus configured to measure one or more properties of a modified target after a target has interacted with the amplified light beam, and to determine a moment when the modified target achieves a reference calibration state; and a control apparatus configured to: receive the reference calibration state and the moment at which the reference calibration state is achieved from the target metrology apparatus; determine a light beam calibration state of the amplified light beam based on the received reference calibration state and the moment at which the reference calibration state is achieved; and provide the light beam calibration state to the light beam metrology apparatus.

Abstract: Degradation of the reflectivity of one or more reflective optical elements in a system for generating EUV radiation is reduced by the controlled introduction of a gas into a vacuum chamber containing the optical element. The gas may be added to the flow of another gas such as hydrogen or alternated with the introduction of hydrogen radicals.

Abstract: Degradation of the reflectivity of one or more reflective optical elements in a system (SO) for generating EUV radiation is reduced by the controlled introduction of a gas into a vacuum chamber (26) containing the optical element. The gas may be added to the flow of another gas such as hydrogen or alternated with the introduction of hydrogen radicals.

Abstract: An immersion lithography apparatus is disclosed in which liquid is supplied to a space between a projection system and a substrate, and a plate structure is provided to divide the space into two parts. The plate structure has an aperture to allow transmission of the projection beam, has through holes in it to reduce the damping effect of the presence of the plate and optionally has one or more inlets and outlets to provide various flows around the aperture in the plate. An embodiment of the invention may reduce the transportation of contaminants, stray light, temperature gradients, and/or the effect of bubbles on the imaging quality.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: An immersion lithographic apparatus has adaptations to prevent or reduce bubble formation in one or more gaps in the substrate table by preventing bubbles escaping from the gap into the beam path and/or extracting bubbles that may form in the gap.

Abstract: A mask assembly suitable for use in a lithographic process, the mask assembly comprising a patterning device; and a pellicle frame configured to support a pellicle and mounted on the patterning device with a mount; wherein the mount is configured to suspend the pellicle frame relative to the patterning device such that there is a gap between the pellicle frame and the patterning device; and wherein the mount provides a releasably engageable attachment between the patterning device and the pellicle frame.

Abstract: Tooling for a mask assembly suitable for use in a lithographic process, the mask assembly comprising a patterning device; and a pellicle frame configured to support a pellicle and mounted on the patterning device with a mount; wherein the mount provides a releasably engageable attachment between the patterning device and the pellicle frame.

Abstract: Degradation of the reflectivity of one or more reflective optical elements in a system (SO) for generating EUV radiation is reduced by the controlled introduction of a gas into a vacuum chamber (26) containing the optical element. The gas may be added to the flow of another gas such as hydrogen or alternated with the introduction of hydrogen radicals.

Abstract: Tooling for a mask assembly suitable for use in a lithographic process, the mask assembly comprising a patterning device; and a pellicle frame configured to support a pellicle and mounted on the patterning device with a mount; wherein the mount provides a releasably engageable attachment between the patterning device and the pellicle frame.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: An immersion lithographic apparatus has adaptations to prevent or reduce bubble formation in one or more gaps in the substrate table by preventing bubbles escaping from the gap into the beam path and/or extracting bubbles that may form in the gap.

Abstract: A lithographic apparatus has a support structure configured to support a patterning device, the patterning device serving to pattern a radiation beam according to a desired pattern and having a planar main surface through which the radiation beam passes; an outlet opening configured to direct a flow of a gas onto the patterning device; and an inlet opening configured to extract the gas which has exited the outlet opening, wherein the outlet opening and inlet opening are in a facing surface facing the planar main surface of the patterning device.

Abstract: A support apparatus configured to support an object, the support apparatus includes a support body including an object holder to hold an object; an opening in the support body adjacent to an edge of the object holder; a channel in fluid communication with the opening via each of a plurality of passageways in the support body; and a passageway liner mounted in at least one of the plurality of passageways, the passageway liner being thermally insulating to substantially thermally decouple the support body from fluid in the at least one of the plurality of passageways.

Abstract: An immersion lithographic apparatus is disclosed in which at least a part of the liquid supply system (which provides liquid between the projection system and the substrate) is moveable in a plane substantially parallel to a top surface of the substrate during scanning. The part is moved to reduce the relative velocity between that part and the substrate so that the speed at which the substrate may be moved relative to the projection system may be increased.

Abstract: A method for manufacturing a membrane assembly for EUV lithography, the method comprising: providing a stack comprising a planar substrate and at least one membrane layer, wherein the planar substrate comprises an inner region and a border region around the inner region; positioning the stack on a support such that the inner region of the planar substrate is exposed; and selectively removing the inner region of the planar substrate using a non-liquid etchant, such that the membrane assembly comprises: a membrane formed from the at least one membrane layer; and a border holding the membrane, the border formed from the border region of the planar substrate.