Abstract: A method for calibrating an auxiliary sensor system is provided. The auxiliary sensor system measures a position of a grating relative to a reference, the grating forming part of an encoder measurement system. The encoder measurement system is adapted to measure a position of a substrate table of a lithographic apparatus and further comprises a sensor mounted to the substrate table. The method comprises exciting the grating to make a movement in at least one measurement direction of the auxiliary sensor system, obtaining an auxiliary sensor system output signal from the sensor system during the movement, and adjusting a parameter of the auxiliary sensor system based on the output signal obtained during the movement to thereby calibrate the auxiliary sensor system.

Abstract: A gas bearing has a first bearing part defining a first bearing surface and a second bearing part defining a second bearing surface. Between the first bearing surface and the second bearing surface there is a gap. A gas supply device supplies a gas to the gap. The first bearing part is at least partly ferromagnetic, and the second bearing part has at least one permanent magnet interacting with the first bearing part for pre-tensioning the gas bearing. The gas bearing may be part of a lithographic apparatus.

Abstract: The invention provides a height detecting apparatus for a lithographic apparatus. The height mapping apparatus includes a height mapping unit for providing at least one height map of a top surface of an object to be placed in a radiation beam of the lithographic apparatus, the object to be clamped by a clamping force applied thereto on a support constructed to support the object. The height mapping apparatus also includes a control unit for controlling the mapping unit to provide the at least one height map of the object relative to at least two different clamping pressure levels.

Abstract: A method for calibrating an auxiliary sensor system is provided. The auxiliary sensor system measures a position of a grating relative to a reference, the grating forming part of an encoder measurement system. The encoder measurement system is adapted to measure a position of a substrate table of a lithographic apparatus and further comprises a sensor mounted to the substrate table. The method comprises exciting the grating to make a movement in at least one measurement direction of the auxiliary sensor system, obtaining an auxiliary sensor system output signal from the sensor system during the movement, and adjusting a parameter of the auxiliary sensor system based on the output signal obtained during the movement to thereby calibrate the auxiliary sensor system.

Abstract: The invention relates to a method for positioning a substrate relative to a substrate table, is presented. When the substrate is positioned on the substrate table for a first time, a first relative position of the substrate with respect to the substrate table is determined. When the substrate is positioned on the substrate table a second subsequent time, a second relative position of the substrate with respect to the substrate table is determined and the position of the substrate table with respect to the substrate is adjusted based on the first and second relative positions, so that the substrate is positioned with respect to the substrate table substantially equally to the first relative position.

Abstract: A lithographic projection apparatus includes a beam production system for projecting a patterned beam of radiation onto a target portion of a substrate, and a support table for supporting an article. The support table has a support surface and an array of protrusions extending from the support surface to support the article on the protrusions. The apparatus also includes a detector for detecting height deviations of the protrusions that affect a surface flatness of the article, a height adjustment device arranged to independently modify a height of the individual protrusions when the support table is operable in the apparatus, and a controller coupled between the detector and the height adjustment device and arranged to control the height adjustment device to adjust the height of the protrusions corresponding to the detected height deviations of the protrusions that affect the surface flatness of the article.