Abstract: A stage apparatus includes X- and Y-axis laser interferometers each of which measures the position a stage, a wavelength compensator which compensates for the wavelength change of a laser beam from each of the X- and Y-axis laser interferometers, a fan duct which is connected to a thermoregulator for supplying a temperature-controlled gas and supplies the temperature-controlled gas to the optical axes of the X- and Y-axis laser interferometers, and a fan duct which is connected to the thermoregulator and supplies the temperature-controlled gas to the wavelength compensator. The time necessary for supplying the temperature-controlled gas from the thermoregulator to the optical axes of the X- and Y-axis laser interferometers through the fan duct is equal to the time necessary for supplying the temperature-controlled gas from the thermoregulator to the wavelength compensator through the fan duct.

Abstract: A lithographic apparatus includes a displacement measuring system configured to measure the position of a substrate table in at least three degrees of freedom. The displacement measuring system includes a first x-sensor configured to measure the position of the substrate table in a first direction and a first and a second y-sensor configured to measure the position of the substrate table in a second direction. Said displacement measuring system further comprises a second x-sensor. The first and second x-sensor and first and second y-sensors are encoder type sensors configured to measure the position of each of the sensors with respect to at least one grid plate. The displacement measuring system is configured to selectively use, depending on the position of the substrate table, three of the first and second x-sensors and the first and second y-sensors to determine the position of the substrate table in three degrees of freedom.

Abstract: A means and a method for determining the spatial position of at least one moving element (9, 20) of a coordinate measuring machine (1) are disclosed. At least one laser interferometer (24) directs a measurement beam (23) to the moving element (9, 20). At least one laser interferometer directs a further measurement beam to the moving element to determine a rotation of the moving element (9, 20) around an X-coordinate direction or around a Y-coordinate direction or around a Z-coordinate direction.

Abstract: In an exposure apparatus having a plurality of substrate stages moving between a plurality of stations, errors due to the combination of the stage and a position measuring unit, such as Abbe error and errors due to the surface configuration of a reflection mirror, are precisely corrected to reduce the position error of the substrate stage. The exposure apparatus includes a control device having a storage unit and a correction unit. The storage unit stores the correction information established every combination of the plurality of substrate stages and a plurality of position measuring units, and the correction unit corrects the result measured by the plurality of position measuring units on the basis of the correction information corresponding to the combination of the substrate stages and the position measuring units among pieces of correction information stored in the storage unit.

Abstract: A method and a coordinate measuring machine (1) are provided, wherein the non-linearities of an interferometer (24) can be corrected. A measuring stage (20) traversable in a plane (25a) is provided for measurement. The substrate (2) is placed in a measuring stage (20); wherein the position of the measuring stage (20) along each of the motion axes is determined by at least one interferometer (24) in each case. A computer (16) is provided for compensating the non-linearity inherent in each of the interferometers (24), wherein the position of the measuring stage (20) to be determined by the interferometers (24) is arranged along a trajectory (52, 60, 67) of the measuring stage (20), which is composed at least partially of components of the axes.

Abstract: First positional information of a stage is measured using an interferometer system, for example, an X interferometer and a Y interferometer. At the same time, second positional information of the stage is measured using an encoder system, for example, one X head and one Y head. A coordinate offset is set by performing a moving average of the difference between the first positional information and the second positional information for over a predetermined measurement time, and the reliability of output signals of the encoder system is verified using the coordinate offset. In the case the output signals are determined to be normal, the stage is servocontrolled using the sum of the first positional information and the coordinate offset. Such servocontrol by a hybrid method makes it possible to perform drive control of the stage having stability of the interferometer and accuracy of the encoder together.

Abstract: A system and a method for determining positions of structures on a substrate are disclosed. The system includes at least one measurement table (20) movable in the X-coordinate direction and in the Y-coordinate direction, a measurement objective (9) and a camera for determining the positions of the structures (3) on the substrate (2). The position of the measurement objective (9) and/or the measurement table (20) may be determined by at least one interferometer (24). The system is surrounded by a housing representing a climatic chamber (50) provided with an active pressure regulation.

Abstract: An improved lithographic interferometer system, is presented herein. The lithographic interferometer system comprises a beam generating mechanism, mirrors which reflect those beams, and detection devices for detecting an interference pattern of overlapping reflected beams. The beam generating mechanism comprises a beam-splitter, which splits the beams into reference beams and measuring beams, a reference mirror that provides a plane mirror interferometer, and a reflective surface that emits at least one reference beam used in a differential plane mirror interferometer.

Abstract: A coordinate measuring machine (1) with vibration decoupling is disclosed, and a method for vibration damping or decoupling is realized. There is provided a measurement table (20) movable in the X-coordinate direction and in the Y-coordinate direction, which is essentially movable in one plane (25a). A controller (16) is connected to the vibration dampers (26) and the measurement table (20), wherein the controller (16) determines the influence of the measurement table (20) on the vertical position alterations of the coordinate measuring machine (1) from an impending or predetermined movement path (30) of the measurement table (20) and controls the vibration dampers (26) such that the position alterations caused by the influence of the measurement table (20) are compensated.

Abstract: An apparatus and method are disclosed for imaging a diffraction grating with a very high depth of focus, using a highly accurate code plate position measurement system. Positions may be measured to an accuracy of 1 nm or even smaller. The system may be used in fields such as manufacturing integrated circuits, and low- and very-low-frequency geophones, and other low- and very-low-frequency acoustic detectors.

Abstract: Process tools and methods are disclosed that involve interferometric and other measurements of movements and positions relative to a process position, such as movements and positions of a stage relative to a lithographic optical system. An exemplary apparatus includes a stage that places a workpiece relative to the tool, and that is movable in at least one direction relative to the tool. At least one first interferometer system is situated relative to the stage to determine stage position in a movement direction relative to the process position. A movement-measuring device determines displacement of the tool from the process position. Using data from the interferometer system and movement-measuring device a processor determines a position of the stage relative to the tool. The processor also corrects the determined position for displacement of the tool.

Abstract: The disclosure features multiple degree-of-freedom interferometers (e.g., non-dispersive interferometers) for monitoring linear and angular (e.g., pitch and/or yaw) displacements of a measurement object with compensation for variations in the optical properties of a gas in the interferometer measurement (and/or reference) beam paths. The disclosure also features interferometry systems that feature an array of interferometers (e.g., including one or more multiple degree-of-freedom interferometer), each configured to provide different information about variations in the optical properties of the gas in the system. Multiple degree-of-freedom interferometers are also referred to as multi-axis interferometers.

Abstract: A measuring apparatus for determining relative positions of a positioning stage arranged in a moveable fashion in at least one direction by a predeterminable maximum traversing path. The measuring device comprises at least one interferometric measuring means and at least one interferometric correction means. An interferometric measuring means is operable with the laser light of a laser of at least one wavelength. Correction results can be generated with the interferometric correction means allowing conclusions to be drawn with respect to the actual wavelength of the laser light during a position determination of the positioning stage in order to take into account variations of the wavelength of the laser light, in particular due to ambient conditions, when evaluating the measuring results. The interferometric correction means is arranged proximate to the interferometric measuring means, and the proximity corresponds to a predeterminable portion of the maximum traversing path of the positioning stage.

Abstract: A lithographic interferometer system includes a beam generating mechanism, mirrors which reflect those beams, and detection devices configured to detect an interference pattern of overlapping reflected beams. The beam generating mechanism includes a beam-splitter, which splits the beams into reference beams and measuring beams, a reference mirror that provides a plane mirror interferometer, and a reflective surface that emits at least one reference beam used in a differential plane mirror interferometer.

Abstract: A method for aligning a substrate in a lithographic apparatus, the method including irradiating a first target portion of the substrate with a first patterned beam to form a first pattern on the substrate. Then, a second target portion of the substrate is irradiated with a second pattern beam to form a second pattern on the substrate. The second target portion at least partly overlaps the first target portion. A diffraction beam is detected during irradiation of the second pattern, due to a diffraction of the second patterned beam on the first pattern. The diffraction beam is compared with a desired diffraction beam, and the substrate is aligned based on a comparison between the detected diffraction beam and the desired diffraction beam.

Abstract: Disclosed is an exposing apparatus which projects an image of a pattern by a projection optical system, comprising a measuring unit having a sensor which measures a positional relationship between the projection optical system and a member which is positioned in relation to the projection optical system, and a first support device which has a first soft structure and which supports the measuring unit in a hanging manner separately from the projection optical system.

Abstract: Interferometer systems for measuring displacement include a displacement interferometer. This interferometer includes a displacement converter responsive to a measuring beam of light. The displacement converter is configured to transform movement thereof in a direction orthogonal to the measuring beam of light into a change in path length between a reflective surface of the displacement converter and the measuring beam of light. The displacement converter may include a transmission grating and a displacement mirror or a reflecting grating.

Abstract: In general, in one aspect, the invention features methods that include locating a plurality of alignment marks on a moveable stage, interferometrically measuring a position of a measurement object along an interferometer axis for each of the alignment mark locations, and using the interferometric position measurements to derive information about a surface figure of the measurement object. The position of the measurement object is measured using an interferometry assembly and either the measurement object or the interferometry assembly are attached to the stage.

Abstract: A method of speckle size and distribution control and the optical system using the same are disclosed. The optical system is arranged inside a housing of a computer mouse that is primarily composed of a laser unit, a lens set, an image sensing unit and a digital signal processing unit. It is known that by projecting a laser beam onto a surface with sufficient roughness, the surface will exhibits a speckled appearance as the speckle pattern is a random intensity pattern produced by the mutual interference of coherent laser beam that are subject to phase differences and/or intensity fluctuations.

Abstract: Improved systems, apparatus, and methods for detecting positions of moving stages and accurately compensating position error during operation (in “real time”) are provided. For some embodiments, rather than rely on two dimensional position measurements, measurements in at least three dimensions may be taken allowing compensation for pitch and roll and, therefore, more accurate position measurements. Further, by including a measurement of a beam column, compensation for movement of the beam may be performed.

Abstract: Defects are prevented from occurring during an exposure process by detecting vibration of and measuring the relative position of components of the exposure apparatus. The exposure apparatus includes an external frame on which a reference mirror is disposed, a projection lens, a first mirror fixed relative to the projection lens, a wafer stage, a second mirror fixed relative to the wafer stage, and an interferometer system that detects vibration of the projection lens using the reference mirror and the first mirror and detects the position of the wafer stage relative to the projection lens using the first and second mirrors. A second interferometer system may be provided to detect vibration of the first interferometer system.

Abstract: A method for processing a signal in an interferometer system that measures position information of an object under measurement based on reflected light obtained by directing a measurement light onto the object under measurement, includes a delaying step of obtaining a delayed signal by causing a delay of a prescribed number of periods with respect to a prescribed signal; a synthesizing step of obtain a synthesized signal of the prescribed signal and the delayed signal; and a measuring step of measuring position information of the object under measurement using the synthesized signal.

Abstract: In general, in one aspect, the invention features methods that include interferometrically monitoring a distance between an interferometry assembly and a measurement object along each of three different measurement axes while moving the measurement object relative to the interferometry assembly. The methods also include monitoring an orientation angle of the measurement object with respect to a rotation axis non-parallel to the three different measurement axes while the measurement object is moving, determining values of a parameter for different positions of the measurement object from the monitored distances, wherein for a given position the parameter is based on the distances of the measurement object along each of the three different measurement axes at the given position, and deriving information about a surface figure profile of the measurement object from a frequency transform of at least the parameter values.

Abstract: A projection exposure apparatus 100 projects the pattern of an original 6 onto a substrate 7 via a projection optical system PL. The projection exposure apparatus 100 includes an original stage 5 which holds the original 6, a substrate stage 8 which holds the substrate 7, and a measurement unit. The measurement unit includes a Fizeau interferometer IF including an optical unit 17 and mirror 22. The optical unit 17 includes a Fizeau surface which splits a light beam into a reference light beam and a test light beam. The mirror 22 reflects the test light beam having passed through the projection optical system PL. The optical unit 17 is mounted on the original stage 5. The mirror 22 is mounted on the substrate stage 8.

Abstract: An interferometer can achieve a high dynamic range for measurements along vertical and horizontal directions using a first measurement channel providing a high dynamic range measurement of a path including components respectively parallel and perpendicular to the optics-object separation and a second measurement channel providing a high dynamic range measurement with just a perpendicular component. Further, using the same techniques at multiple locations around permits a high dynamic range for measurements of the degrees of freedom of an object.

Abstract: An interferometer provides a large dynamic range for perpendicular displacement measurements. In operation, a measurement reflector on an object reflects a measurement beam to an overlying Porro prism, and a reference reflector on the object returns a reference beam to the interferometer. A second Porro prism in the interferometer can return the reference beam for a second pass to the reference reflector, while the measurement beam complete only one pass. Reductions in beam walk-off result from retroreflections in the Porro prisms and the matching effects that some object rotations have on measurement and reference beams. Perpendicular motion of the object relative to the first Porro prism causes a Doppler shift only in the measurement beam. Accordingly, a beat frequency found when combining the measurement and reference beams can indicate a residual Doppler shift associated with the motion in the perpendicular direction.

Abstract: The present invention provides an apparatus and method for determining displacement along the z-direction of an object, which is fixed in a holder of an apparatus and is illuminated by a beam of radiation, the beam being provided by the apparatus and having an optical axis extending in the z-direction. The method comprises arranging the measuring mirror(s) and/or measuring laser beam of an interferometer system such that no relevant part of the laser beam is parallel to the z-direction. This ensures that the interferometer system and its parts may be arranged away from the beam of radiation, allowing larger diameter projection systems for the beam of radiation, as well as more homogeneous air showers around the object. Thus the quality of the illumination of the object may be improved.

Abstract: In an interferometric displacement measuring system, a correction for beamshear is made. The correction may be a polynomial of a variable proportional to the length of the optical path traversed by the measurement beam and the angle of the measurement mirror. The correction compensates for errors caused by non-planarity of the wavefront of the measurement beam.

Abstract: A lithographic apparatus comprises a substrate table to hold a substrate, a reference structure and a measurement system to measure a position of the substrate table with respect to the reference structure. The measurement system comprises a first measurement system to measure a position of the substrate table with respect to an intermediate structure and a second measurement system to measure a position of the intermediate structure with respect to the reference structure. The intermediate structure may be connected or connectable to a drive mechanism to drive the substrate table. A distance between the substrate table and the intermediate structure, resp. a distance between the intermediate structure and the reference structure may be small which results in a highly accurate position measurement.

Abstract: Improved systems, apparatus, and methods for detecting positions of moving stages and a reference position of a beam column are provided. For some embodiments, independent discrete interferometers may be utilized for distance measurements in each axis, rather than a cumbersome monolithic multi-axis interferometer utilized in conventional systems.

Abstract: Techniques for compensating for geometric effects of beam misalignment in plane mirror interferometers are disclosed.

Abstract: An exposure apparatus includes a projection optical system for projecting an exposure pattern, onto an object to be exposed, and a measuring apparatus for measuring, as an interference fringe, optical performance of the projection optical system, wherein the measuring apparatus includes an optical element having opposing first and second surfaces, wherein the first surface has a first measurement pattern, and the second surface has a second measurement pattern and is closer to the projection optical system than the first measurement pattern, and wherein the measuring apparatus introduces light into the projection optical system via first and second measurement patterns.

Abstract: A two-corner retroreflector that includes a common face positioned to receive two beams and two corners each positioned to receive one of the beams and retro-reflect it back through the common face.

Abstract: In general, in one aspect, the invention features a method for determining the location of an alignment mark on a stage including measuring a location, x1, of a stage along a first measurement axis using an interferometer, measuring a location, x2, of the stage along a second measurement axis substantially parallel to the first measurement axis, and determining a location of the alignment mark along a third axis substantially parallel to the first measurement axis based on x1, x2, and a correction term, ?3, calculated from predetermined information including information characterizing imperfections in the interferometer.

Abstract: A system and method allow for a more effective synchronous scanning mirror (SSM). A lithography apparatus comprises an illumination system, a patterning device, a substrate table, and a projection system. The illumination system conditions a beam of radiation received from a radiation source operating at a first frequency. The patterning device patterns the beam. The substrate table supports and scans a substrate at a scanning velocity. The projection system includes a scanning device including a reflective device and a plurality of flexures. The plurality of flexures being configured to allow the reflective device to resonate about an axis of rotation. The scanning device is configured to scan the patterned beam onto a target area of the substrate The resonant frequency of the scanning device is substantially equal to the first frequency, and is synchronized with the scanning velocity.

Abstract: A laser interferometer is disclosed comprising a housing capable of being substantially repeatably mounted to a wall of an environmental chamber, the housing including a laser source, a reflector attached to an object located within the environmental chamber, and a light passage provided through the wall of the environmental chamber enabling passage of a laser beam from the laser source to the reflector. At least one beam steerer may be provided for adjusting direction of passage of a laser beam through the light passage. Also disclosed is a column laser interferometer.

Abstract: A method for the high-precision measurement of coordinates on a substrate is disclosed. The substrate is placed on a stage moveable in X/Y coordinate directions. First, a plurality of images of a structure on a substrate are imaged by means of a 2-dimensional detector during the relative movement of a measuring objective in Z coordinate direction and the simultaneous movement of the stage in X and Y coordinate directions.

Abstract: An alignment apparatus includes driving means having a movable element and a stator, a measurement unit which measures a position of a moving member moved by the driving means using measurement light, and a discharging unit to discharge gas existing in an optical path of the measurement light. The discharging unit is provided to the stator.

Abstract: A motion system includes a first stage that is configured to rotate about a first axis and a second stage coupled to the first stage that includes an object carrier adapted to position an object in at least one other axis. The motion system has a novel arrangement of laser interferometer elements and axes of motion. The arrangement permits accurate and precise measurement of a position of the object carrier in up to three (or more) axes of motion even as the first stage of the motion system is tilted through relatively large angles. The novel arrangement of the axes of motion also enables very precise control of the position of the object carrier even at high tilt angles.

Abstract: In general, in one aspect, the invention features a method that includes monitoring a position of a stage along a first measurement axis and a second measurement axis of a multi-axis interferometry system and determining a position of the stage with respect to another degree of freedom based on the monitored positions along the first and second axes and predetermined information about how the measurement axes deviate from being parallel to one another.

Abstract: In one aspect, the invention features a method, including using an interferometer in an interferometry system to produce an output beam comprising a phase related to an optical path difference between a path of a first beam and a path of a second beam, wherein the first beam contacts a measurement object at a first location and the first or second beam contacts the measurement object at a second location, and wherein the first and second locations are different, providing precalibrated information that accounts for contributions to the optical path difference caused by a deviation of the path of the first or second beam from a nominal beam path due to an imperfection of the measurement object at the first location and due to an imperfection of the measurement object at the second location, and determining a position of the measurement object with respect to at least one degree of freedom based on information derived from the output beam and the precalibrated information.

Abstract: A lithographic apparatus includes an object support configured to support an object. The apparatus further includes X, Y and Z interferometer measurement systems, and an object support positioning system configured to position the object support in a number of degrees of freedom on the basis of measurements of the interferometer measurement systems. A calibration device is configured to measure Ry of the object support with the X interferometer measurement system in at least two different Z positions, measure Ry of the object support with the Z interferometer measurement system in at least two different Z positions, calibrate a linear Z dependency of Ry on the basis of the measurements, and calibrating a linear X dependency of Z on the basis of the previous calibration. Similarly, a linear Y dependency of Z is calibrated.

Abstract: In general, in one aspect, the invention features methods that include interferometrically monitoring a distance between an interferometry assembly and a measurement object along each of three different measurement axes while moving the measurement object relative to the interferometry assembly, determining values of a first parameter and a second parameter for different positions of the measurement object from the monitored distances, wherein for a given position the first parameter is based on the monitored distances of the measurement object along each of the three different measurement axes at the given position, and for a given position the second parameter is based on the monitored distance of the measurement object along each of two of the measurement axes at the given position, and deriving information about a surface figure profile of the measurement object from the first and second parameter values.

Abstract: A stage apparatus including a stage movable in a first direction and a second direction, different from the first direction, the first and second directions being a horizontal direction, and first and second measurement systems each having a laser interferometer and a mirror system including a first reflecting mirror elongated in the first direction and a second reflecting mirror elongated in the second direction, and measuring a position of the stage with respect to a vertical direction based on measurement of a length of a laser beam light path formed by the mirror system. A switching unit transfers a measurement value from the first measurement system in use to the second measurement system and switches the measurement system in use from the first measurement system to the second measurement system within an overlapping zone of measurement systems. A first correcting unit corrects the transferred measurement value.

Abstract: In general, in one aspect, the invention features a method for determining the location of an alignment mark on a stage including measuring a location, x1, of a stage along a first measurement axis using an interferometry system, measuring a location, x2, of the stage along a second measurement axis parallel to the first measurement axis, and determining a location of the alignment mark along a third axis parallel to the first measurement axis based on x1, x2, and a correction term, ?3, calculated from predetermined information including information characterizing imperfections in the interferometry system determined using the interferometry system and the stage.

Abstract: A lithographic apparatus includes a position quantity determination system to determine a position quantity of a movable part which is in operation at least partly surrounded by an area comprising a fluid. The position quantity determination system includes an interferometer system, a global sensor to determine a global value of a physical quantity of the fluid in the area, and a local sensor to determine a local value of the physical quantity of the fluid in the part of the area. The position quantity determination system is configured to determine the position quantity from an output of the interferometer, the global value of the physical quantity and the local value of the physical quantity. The physical quantity may include a pressure, a temperature, etc. The local physical quantity determination system may include a sensor, such as a high-speed sensor, a computational fluid dynamics model or a linear approximation model.

Abstract: In general, in one aspect, the invention features a method that includes directing a first measurement beam along a first path contacting a measurement object to determine a first interferometric phase related to a position of a measurement object, directing a second measurement beam along a second path contacting the measurement object to determine an second interferometric phase related to the position of the measurement object, and determining a contribution to the first interferometric phase due to perturbations in refractivity along the first path based on the second interferometric phase.

Abstract: In general, in a first aspect, the invention features a method for determining the location of an alignment mark on a stage, which includes directing a measurement beam along a path between an interferometer and a mirror, wherein at least the interferometer or the mirror is mounted on the stage, combining the measurement beam with another beam to produce an output beam comprising information about the location of the stage, measuring from the output beam a location, x1, of the stage along a first measurement axis, measuring a location, x2, of the stage along a second measurement axis substantially parallel to the first measurement axis, calculating a correction term, ?3, from predetermined information characterizing surface variations of the mirror for different spatial frequencies, wherein contributions to the correction term from different spatial frequencies are weighted differently, and determining a location of the alignment mark along a third axis parallel to the first measurement axis based on x1, x2,

Abstract: Spatial filtering of beams in interferometry systems is used to reduce a displacement of the beams from an optical path corresponding to the path of the beams in an optimally-aligned system. By reducing beam displacement from the optical path, the system reduces the magnitude of beam shears and associated non-cyclic errors in linear and angular displacements measured by the interferometry systems.

Abstract: A lithographic apparatus includes an interferometer configured to measure a position of a mirror of the lithographic apparatus. For measuring unflatness of the mirror the interferometer includes a modulator configured to modulate a position of an input beam of the interferometer, a synchronous detector configured to synchronously detect an interfered, modulated beam, and a calculator configured to calculate an unflatness of an area of the mirror from an effect of the modulation of the position of the input beam on an output signal of the synchronous detector. The modulator can include a rotatable, tilted, plan plate.