Abstract: A position measurement system to measure a position of an object relative to a reference, the position measurement system including two interferometers, wherein each interferometer is configured to form a reference beam and a measurement beam from input radiation and to combine the reference beam and the measurement beam to provide output radiation to be delivered to a detector, wherein each interferometer is configured such that the reference beam is formed by reflection of input radiation from a reflective element, and such that the measurement beam is formed by diffraction of input radiation from a grating on the object, and wherein the reference beam and the measurement beam are parallel to each other.

Abstract: A measurement system configured to measure a position dependent signal of an object table, the measurement system including at least one sensor mountable on the object table and a sensor target object mountable on a substantially stationary frame, and a mounting device configured to mount the sensor target object on the substantially stationary frame, wherein the measurement system further includes a compensator configured to compensate movements and/or deformations of the sensor target object with respect to the substantially stationary frame. The compensator may include a passive or an active damper and/or a feedback position controller. In an alternative embodiment, the compensator includes a gripping device which fixes the position of the sensor target object during a high accuracy movement of the movable object.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: A measurement system configured to measure a position dependent signal of an object table, the measurement system including at least one sensor mountable on the object table and a sensor target object mountable on a substantially stationary frame, and a mounting device configured to mount the sensor target object on the substantially stationary frame, wherein the measurement system further includes a compensator configured to compensate movements and/or deformations of the sensor target object with respect to the substantially stationary frame. The compensator may include a passive or an active damper and/or a feedback position controller. In an alternative embodiment, the compensator includes a gripping device which fixes the position of the sensor target object during a high accuracy movement of the movable object.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: A measurement system configured to measure a position dependent signal of an object table, the measurement system including at least one sensor mountable on the object table and a sensor target object mountable on a substantially stationary frame, and a mounting device configured to mount the sensor target object on the substantially stationary frame, wherein the measurement system further includes a compensator configured to compensate movements and/or deformations of the sensor target object with respect to the substantially stationary frame. The compensator may include a passive or an active damper and/or a feedback position controller. In an alternative embodiment, the compensator includes a gripping device which fixes the position of the sensor target object during a high accuracy movement of the movable object.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: A position measurement system includes a first part and a second part for determining a position of a first member relative to a second member by providing a position signal representing a position of the first part relative to the second part, and a computational unit comprising an input terminal for receiving the position signal. The computational unit is configured to, in use, apply a conversion to the position signal to obtain a signal representing a position of the first member relative to the second member; and apply an adjustment to the conversion to at least partly compensate for a drift of the first part or the second part or both. The adjustment is based on a predetermined drift characteristic of the first part or the second part or both respectively. The predetermined drift characteristic includes one or more base shapes of the first part and/or the second part.

Abstract: A lithographic apparatus includes a stage to hold an object, the stage being moveable relative to a reference structure in a motion range; a magnet structure to provide a spatially varying magnetic field in at least a part of the motion range, the magnet structure being moveable relative to the reference structure and the stage; a first position measurement system to provide a first measurement signal corresponding to a position of the stage and/or the object in a measurement direction relative to the reference structure; a second position measurement system to provide a second measurement signal corresponding to a position of the stage relative to the magnet structure; and a data processor to correct the first measurement signal with a value dependent on the second measurement signal to provide a corrected first measurement signal representative of the position of the stage and/or the object relative to the reference structure in the measurement direction.

Abstract: A position measurements system to measure a position of a movable object with respect to another object includes two or more one dimensional (1D) encoder heads mounted on one of the movable object and the other object and each capable of emitting a measurement beam along a measurement direction, one or more reference targets mounted on the other of the movable object and the other object, each reference target including a planar surface with a grid or grating to cooperate with the two or more one dimensional (1D) encoder heads, and a processor to calculate a position of the object on the basis of outputs of the two or more 1D encoder heads, wherein the measurement direction of each of the two or more 1D encoder heads is non-perpendicular to the planar surface of the respective reference target.

Abstract: A lithographic apparatus is disclosed that includes an encoder type sensor system configured to measure a position of a substrate table of the lithographic apparatus relative to a reference structure. The encoder type sensor system includes an encoder sensor head and an encoder sensor target and the lithographic apparatus comprises a recess to accommodate the encoder sensor target.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: An encoder-type measurement system is configured to measure a position dependent signal of a movable object. The measurement system includes a light source and a sensor. The light source and the sensor are mounted on one of the movable object or a substantially stationary frame. The measurement system also includes a reference object that includes a grating or grid mounted on the other of the movable object or the substantially stationary frame. The light source is configured to emit a light beam towards the reference object. The sensor is configured to detect light of the light source reflected by the reference object. The measurement system also includes an error detector capable of detecting errors in or on the grating or grid of the sensor target object during a continuous production process.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: A position measurement system to measure a position of a movable stage includes a reference plate; a plurality of sensors arranged such that, depending on a position of the movable stage relative to the reference plate, at least a subset of the plurality of sensors is configured to cooperate with the reference plate to provide for each of the sensors in the subset respective sensor signals representative of a position of the respective sensor relative to the reference plate; and a processor arranged to determine from the sensor signals a stage position, the processing device configured so as to, when the stage is in a position where an over-determined number of sensor signals is provided by at least the subset of the sensors that are in operational cooperation with the reference plate, (a) determine the stage position from a subset of the over-determined number of sensor signals, and (b) correct a sensor signal of one or more of the sensors from a discrepancy between the determined stage position and a remain

Abstract: A lithographic apparatus includes an illumination system configured to condition a radiation beam, a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam, a substrate support constructed to hold a substrate, and a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein the substrate support includes parts that are made of an open cell plastic foam material.

Abstract: A position measurement system includes a first part and a second part for determining a position of a first member relative to a second member by providing a position signal representing a position of the first part relative to the second part, and a computational unit comprising an input terminal for receiving the position signal. The computational unit is configured to, in use, apply a conversion to the position signal to obtain a signal representing a position of the first member relative to the second member; and apply an adjustment to the conversion to at least partly compensate for a drift of the first part or the second part or both. The adjustment is based on a predetermined drift characteristic of the first part or the second part or both respectively. The predetermined drift characteristic includes one or more base shapes of the first part and/or the second part.

Abstract: A stage system includes a movable stage, at least two encoder heads each constructed to provide an encoder signal representative of a position of the movable stage with respect to an encoder target structure, and a controller to control a position of the stage. The controller is provided with the encoder signals of each of the encoder heads. The controller is arranged to apply a weighting function to the encoder signals and to derive a position of the stage from the weighted encoder signals.

Abstract: A lithographic apparatus including a substrate table position measurement system and a projection system position measurement system to measure a position of the substrate table and the projection system, respectively. The substrate table position measurement system includes a substrate table reference element mounted on the substrate table and a first sensor head. The substrate table reference element extends in a measurement plane substantially parallel to the holding plane of a substrate on substrate table. The holding plane is arranged at one side of the measurement plane and the first sensor head is arranged at an opposite side of the measurement plane. The projection system position measurement system includes one or more projection system reference elements and a sensor assembly. The sensor head and the sensor assembly or the associated projection system measurement elements are mounted on a sensor frame.

Abstract: In an embodiment, a stage system calibration method includes moving the stage relative to an encoder grid in response to a setpoint signal and measuring a position of the stage by a sensor head cooperating with the encoder grid. The position of the stage is controlled by a stage controller. A signal representative of a difference between the setpoint signal and the position of the stage as measured by the sensor head is registered. The stage system is calibrated from the registered signal representative of the difference.