Abstract: Methods and apparatus for maintaining the thermal equilibrium of a substrate and an immersion lithographic apparatus are disclosed using or having a timetable comprising information regarding the position, speed and/or acceleration of the substrate; and an evaporation controller and/or condensation controller acting to decrease localized evaporation and/or increase localized condensation in response to the information in the timetable. Evaporation of liquid from the surface of the substrate cools it down, while condensing liquid on its bottom surface heats the substrate locally.

Abstract: A method for filtering a fluid to obtain a fluid having a known purity is described. The fluid is filtered with a filtration system, and upstream of a final filtration stage of the filtration system, a purity of the fluid is measured. A purity of the fluid filtered by the filtration system is determined by correcting the measured purity with a filtration behavior of the final filtration stage. In an embodiment, the fluid comprises an ultra pure water for use as an immersion liquid in a lithographic apparatus.

Abstract: In an immersion lithography apparatus in which, for example, immersion liquid is supplied to a localized space, a plate is provided to divide the space into two parts. Such a division of the space may facilitate reduction of stray radiation, a temperature gradient, and the transportation of contaminants.

Abstract: In a scanning immersion lithographic apparatus, immersion liquid is supplied on one side of the space between the projection system and the substrate and drained on the other side so that the flow of liquid is substantially perpendicular to the scan direction.

Abstract: A lithographic apparatus is disclosed. The apparatus includes a support constructed to support a patterning device, the patterning device being capable of imparting a radiation beam with a pattern in its cross-section to form a patterned radiation beam. A projection system is configured to project the patterned radiation beam onto a target portion of a substrate. A first vacuum environment contains the projection system, a second vacuum environment contains the patterning device support, and a separator separates the first and second vacuum environments. The separator includes an aperture for passing the projection beam from the first vacuum environment towards the patterning device and/or vice-versa. The patterning device forms at least part of a seal for substantially sealing the aperture of the separator.