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: A lithographic apparatus comprises a substrate table to hold a substrate and a projection system to project a patterned radiation beam onto a target portion of the substrate. The lithographic apparatus further comprises a fluid supply system to supply a fluid between the substrate and a final lens element of the projection system as well as a position controller to control a position of the fluid supply system. The position controller is configured to, being provided with a position quantity of the substrate, determine a desired position of the liquid supply system by adding a position offset to the position quantity of the substrate, and position the liquid supply system according to the desired position. The position quantity may comprise a position and/or rotational position of the substrate table and/or a height function of a substrate height.

Abstract: A lithographic apparatus that includes an exposure system and a measurement system, is presented. The exposure system projects a patterned beam onto a target portion of a first substrate, while the measurement system projects a measurement beam on a target portion of a second substrate. Movement of a movable part of the apparatus generates a disturbance in a position of another movable part of the apparatus, e.g. due to displacement of air. This error can be compensated by calculating a compensation signal which is a function of states of one or both of the movable parts.