Abstract: A calibration method to calibrate a substrate table position in a lithographic apparatus, the method including repeatedly irradiating a pattern onto a surface of the substrate so as to create a two dimensional arrangement of patterns on the surface of the substrate, the irradiating including displacing the substrate table between successive irradiations to irradiate the pattern onto different locations on the surface of the substrate, reading out the patterns in the two dimensions to obtain pattern read out results, deriving incremental position deviations from the read out results of neighbouring patterns in dependency on the position of the substrate table in the two dimensions, deriving from the incremental position deviations a position error of the substrate table as a function of the two dimensional position of the substrate table and calibrating the position of the substrate table using the position dependent position error.

Abstract: A device manufacturing method includes projecting a patterned beam of radiation onto a substrate, wherein the position of a movable object is determined in a number of degrees of freedom using a number of sensors, the number of sensors being larger than the number of degrees of freedom, wherein the position of the movable object in the number of degrees of freedom is determined using signals of each of the sensors, wherein the signals of the sensors are weighed on the basis of the difference between noise levels of each of the sensors. Accuracy of the position measurement of movable object and/or overlay and focus performance are improved in lithographic apparatus.

Abstract: A lithographic projection apparatus including an illumination system configured to provide a beam of radiation, a support configured to support a patterning device, the patterning device configured to impart the beam with a pattern in its cross section, a substrate table configured to hold a substrate, a projection system configured to project the patterned radiation onto a target portion of the substrate, a plurality of level sensors for sensing a level of a substrate carried on the substrate table at a plurality of different positions, and a system for determining the position of the substrate table.

Abstract: The invention pertains to a measurement system for measuring displacement of a moveable object relative to a base in at least a first direction of measurement, the moveable object having at least one reference part that is moveable in a plane of movement relative to the base, the actual movements of the reference part being within an area of said plane of movement that is bounded by a closed contour having a shape. The measurement system comprises a sensor head that operatively communicates with a planar element. The sensor head is mounted onto the base and the planar element being mounted onto the reference part of the moveable object or the other way around, wherein the planar element has a shape that is essentially identical to the shape of the closed contour.