Abstract: A lithographic apparatus comprising an object table which carries an object. The lithographic apparatus may further comprise at least one sensor as part of a measurement system to measure a characteristic of the object table, the environment surrounding the lithographic apparatus or another component of the lithographic apparatus. The measured characteristic may be used to estimate the deformation of the object due to varying loads during operation of the lithographic apparatus, for example varying loads induced by a two- phase flow in a channel formed within the object table. Additionally, or alternatively, the lithographic apparatus comprises a predictor to estimate the deformation of the object based on a model. The positioning of the object table carrying the object can be controlled based on the estimated deformation.

Abstract: A control system for a positioning system, for positioning a driven object, e.g. in a lithographic apparatus, in N dimensions has M sensors, where M>N. A transformation module converts the M measurements by the sensors into a positional estimate in N dimensions taking into account compliance of the driven object.

Abstract: An alignment sensor for a lithographic apparatus is arranged and constructed to measure an alignment of a movable part of the lithographic apparatus in respect of a stationary part of the lithographic apparatus. The alignment sensor comprises a light source configured to generate a pulse train at a optical wavelength and a pulse repetition frequency, a non-linear optical element, arranged in an optical propagation path of the pulse train, the non-linear optical element configured to transform the pulse train at the optical wavelength into a transformed pulse train in an optical wavelength range, an optical imaging system configured to project the transformed pulse train onto an alignment mark comprising a diffraction grating; a detector to detect a diffraction pattern as diffracted by the diffraction grating, and a data processing device configured to derive alignment data from the detected diffraction pattern as detected by the detector.

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 provided having a substrate table including a drain configured to receive immersion fluid which leaks into a gap between an edge of a substrate on the substrate table and an edge of a recess in which the substrate is located. A thermal conditioning system is provided to thermally condition at least the portion of the recess supporting the substrate by directing one or more jets of fluid onto a reverse side of the section supporting the substrate.

Abstract: An immersion lithographic apparatus is provided with a liquid confinement structure which defines at least in part a space configured to contain liquid between the projection system and the substrate. In order to reduce the crossing of the edge of the substrate which is being imaged (which can lead to inclusion of bubbles in the immersion liquid), the cross-sectional area of the space in a plane parallel to the substrate is made as small as possible. The smallest theoretical size is the size of the target portion which is imaged by the projection system. In an embodiment, the shape of a final element of the projection system is also changed to have a similar size and/or shape in a cross-section parallel to the substrate to that of the target portion.

Abstract: A device having a waveguide formed of a continuous body of material that is transparent to radiation that passes through the waveguide, wherein the body has an input surface and an output surface, and a cooler configured to cool the input surface and/or the output surface. An exposure apparatus having a programmable patterning device that comprises a plurality of radiation emitters, configured to provide a plurality of radiation beams; and a projection system, comprising a stationary part and a moving part, configured to project the plurality of radiation beams onto locations on a target that are selected based on a pattern, wherein at least one of the radiation emitters comprises a waveguide configured to output a radiation beam that comprises unpolarized and/or circularly polarized radiation.

Abstract: A lithography tool is calibrated using a calibration substrate having a set of first marks distributed across its surface in a known pattern. The tool is operated to apply a pattern comprising a plurality of second marks at various positions on the substrate, each second mark overlying one of the first marks and being subject to an overlay error dependent on an apparatus-specific deviation. The second marks are applied by multiple exposures while the substrate remains loaded in the tool. An operating parameter of the apparatus is varied between the exposures. An overlay error is measured and used to calculate parameter-specific, apparatus-specific calibration data based on knowledge of the parameter variation used for each exposure.

Abstract: A droplet generator, for an EUV radiation source, comprises: a capillary in which, in use, molten material flows; an actuator configured to modulate a pressure inside the capillary; and a controller configured to drive the actuator at a driving frequency; wherein the droplet generator is arranged such that, in use, the driving frequency is equal or about equal to a main resonance frequency of the molten material in the capillary.

Abstract: A lithographic apparatus includes a driven object having compliant dynamics; a plurality of actuators configured to act on the driven object, wherein the plurality of actuators are over-determined in an actuator degree of freedom; a control system including a transformation matrix configured to generate controller output signals for each of the plurality of actuators in response to a setpoint, wherein the transformation matrix is configured such that the controller output signals do not excite the compliant dynamics of the driven object in at least one degree of freedom.

Abstract: A lithographic process is used to form a plurality of target structures (92, 94) distributed at a plurality of locations across a substrate and having overlaid periodic structures with a number of different overlay bias values distributed across the target structures. At least some of the target structures comprise a number of overlaid periodic structures (e.g., gratings) that is fewer than said number of different overlay bias values. Asymmetry measurements are obtained for the target structures. The detected asymmetries are used to determine parameters of a lithographic process. Overlay model parameters including translation, magnification and rotation, can be calculated while correcting the effect of bottom grating asymmetry, and using a multi-parameter model of overlay error across the substrate.

Abstract: A lithographic apparatus includes a projection system configured to project a patterned radiation beam onto a target portion of a substrate. The projection system has a final element. The apparatus also includes a barrier member surrounding a space between the projection system and, in use, the substrate, to define in part with the final element a reservoir for liquid. The barrier member is spaced from the final element to define a gap therebetween. The apparatus further includes a deformable seal between a radially outer surface of the final element and a radially outer surface of the barrier member. The deformable seal is configured to substantially prevent a gas from flowing past the seal towards or away from the reservoir of liquid.

Abstract: An imprint lithography apparatus includes an actuator configured to displace an imprint template holder relative to a substrate holder to perform an imprint process. The imprint template holder and/or the substrate holder being supported on a support structure, the support structure being mounted to a vibration isolation system that is mounted to a base of the apparatus. The vibration isolation system is configured to provide a vibration isolation of the support structure relative to the base. A control unit is configured to control the actuator during the imprint process. The control unit is arranged to control an adjustable member of the vibration isolation system to adjust a dynamical characteristic of the vibration isolation system during at least part of the imprint process so as to reduce a displacement of the support structure relative to the base due to a force exerted on the support structure during the imprint process.

Abstract: In an embodiment, a lithographic projection apparatus has an off-axis image field and a concave refractive lens as the final element of the projection system. The concave lens can be cut-away in parts not used optically to prevent bubbles from being trapped under the lens.

Abstract: A property of a target structure is measured based on intensity of an image of the target. The method includes (a) obtaining an image of the target structure; (b) defining a plurality of candidate regions of interest, each candidate region of interest comprising a plurality of pixels in the image; (c) defining an optimization metric value for the candidate regions of interest based at least partly on signal values of pixels within the region of interest; (d) defining a target signal function which defines a contribution of each pixel in the image to a target signal value. The contribution of each pixel depends on (i) which candidate regions of interest contain that pixel and (ii) optimization metric values of those candidate regions of interest.

Abstract: An apparatus for cleaning an object, the apparatus including: an object support for supporting the object; a low pressure chamber for exposing a first surface of the object to a low pressure when the object is arranged on the object support, an electrode arranged adjacent to and separated from the first surface of the object when the object is arranged on the object support, the electrode being in electrical communication with a surface of the object support which is adjacent the first surface of the object; and a power supply arranged to apply a voltage between the electrode and the object; thereby generating a discharge between the object and the electrode.

Abstract: A membrane transmissive to EUV radiation, which may be used as a pellicle or spectral filter in a lithographic apparatus. The membrane includes one or more high doped regions wherein the membrane is doped with a dopant concentration greater than 1017 cm?3, and one or more regions with low (or no) doping. The membrane may have a main substrate having low doping and one or more additional layers, wherein the high doped regions are comprised within some or all of the additional layers.

Abstract: A method includes providing a target material that includes a component that emits extreme ultraviolet (EUV) light when converted to plasma; directing a first beam of radiation toward the target material to deliver energy to the target material to modify a geometric distribution of the target material to form a modified target; directing a second beam of radiation toward the modified target, the second beam of radiation converting at least part of the modified target to plasma that emits EUV light; controlling a radiant exposure delivered to the target material from the first beam of radiation to within a predetermined range of radiant exposures; and stabilizing a power of the EUV light emitted from the plasma by controlling the radiant exposure delivered to the target material from the first beam of radiation to within the predetermined range of radiant exposures.

Abstract: A lithographic apparatus comprising a projection system, and a liquid confinement structure configured to at least partly confine immersion liquid to an immersion space defined by the projection system, the liquid confinement structure and a substrate and/or substrate table is disclosed wherein a measure is taken to reduce the effect of droplets and/or a liquid film on the last element of the projection system.

Abstract: An EUV light source is disclosed which may comprise a plurality of targets, e.g., tin droplets, and a system generating pre-pulses and main-pulses with the pre-pulses for irradiating targets to produce expanded targets. The system may further comprise a continuously pumped laser device generating the main pulses with the main pulses for irradiating expanded targets to produce a burst of EUV light pulses. The system may also have a controller varying at least one pre-pulse parameter during the burst of EUV light pulses. In addition, the EUV light source may also include an instrument measuring an intensity of at least one EUV light pulse within a burst of EUV light pulses and providing a feedback signal to the controller to vary at least one pre-pulse parameter during the burst of EUV light pulses to produce a burst of EUV pulses having a pre-selected dose.