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: The present invention relates to a method for calibrating a grating of an encoder measurement system between two adjacent calibrated locations, the method includes moving one of a sensor object including an encoder-type sensor and a grating along the other one of the sensor object and the grating with a speed, wherein the speed is selected such that disturbances in the grating substantially extending over a distance smaller than a distance between the two calibrated locations can not or only partly be followed by the one of the sensor object and the grating, and measuring during the moving the position of the sensor object with respect to the grating at a plurality of locations between the two calibrated locations.

Abstract: A position measurement system for measuring a position of an object is described, the system including: a first incremental measurement unit for measuring a first number of first distance steps in a distance between a reference frame and the object, wherein the first number equals a first integer value plus a first fraction, and a second incremental measurement unit for measuring a second number of second distance steps in a distance between the reference frame and the object, wherein the second number equals a second integer value plus a second fraction, wherein the position measurement system is constructed and arranged to initialize the second incremental measurement unit on the basis of the first number and the second fraction.

Abstract: In a lithographic apparatus, a measurement of the position of an object in an ambient space by an object position measuring system which is influenced by pressure variations in the ambient space, is corrected by an accurate measurement of the pressure in the ambient space. A pressure difference is measured between a pressure in a reference pressure volume and an ambient pressure in an ambient space. An absolute pressure in the reference pressure volume is added to the pressure difference to determine a change of pressure in the ambient space. Alternatively, the pressure difference is integrated over time and a determined change of pressure in the reference pressure volume is added to the pressure difference to determine a change of pressure in the ambient space.

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: A lithographic apparatus has a position measuring apparatus configured to measure a position of a substrate support or a patterning support in a medium. The position measuring apparatus has a barometer to measure a pressure of the medium, thereby providing a pressure signal. The position measuring apparatus has a distance measuring device measuring a reference distance, thereby providing a reference distance signal. The position measuring apparatus has a processor that converts the reference distance signal into a pressure-change signal; processes the pressure-change signal in a similar way as the pressure signal, thereby providing a processed pressure-change signal; determines a difference between the processed pressure-change signal and the pressure signal, thereby providing a drift signal; determines a difference between the pressure-change signal and the drift signal, thereby providing an absolute pressure signal; and corrects a position measurement on the basis of the absolute pressure signal.

Abstract: A lithographic projection apparatus is equipped with a device for manipulation and routing of at least one portion of a metrology beam of radiation. The device includes a first and a second optical wedge, wherein the second optical wedge and the first optical wedge having a relative position with respect to each other. The at least one portion of the metrology beam enters the device along an incoming optical axis at a first major surface of the first optical wedge, passes through the first and second optical wedges, and exits at a second major surface of the second optical wedge. The first and second optical wedges are arranged to at least one of rotate and translate the at least one portion of the metrology beam relative to the incoming optical axis by changing the relative position of the first and the second optical wedges.

Abstract: A lithographic apparatus includes an illumination system configured to condition a radiation beam, and a support structure constructed to support a patterning device. The patterning device imparts the radiation beam with a pattern in its cross-section to form a patterned radiation beam. A substrate table is constructed to hold a substrate, and a projection system projects the patterned radiation beam onto a target portion of the substrate. An interferometer system measures a position of the substrate table, and generates a disturbance frequency by optical feedback. A position control system controls the position of the support structure and the substrate table on the basis of the position measurement of the interferometer system. The position control system selects a substrate table speed to prevent a positioning error due to the disturbance frequency.

Abstract: A lithographic projection apparatus is equipped with a device for manipulation and routing of at least one portion of a metrology beam of radiation. The device includes a first and a second optical wedge, wherein the second optical wedge and the first optical wedge having a relative position with respect to each other. The at least one portion of the metrology beam enters the device along an incoming optical axis at a first major surface of the first optical wedge, passes through the first and second optical wedges, and exits at a second major surface of the second optical wedge. The first and second optical wedges are arranged to at least one of rotate and translate the at least one portion of the metrology beam relative to the incoming optical axis by changing the relative position of the first and the second optical wedges.