Abstract: In an immersion lithographic apparatus, bubble formation in immersion liquid is reduced or prevented by reducing a gap size or area on a substrate table and/or covering the gap.

Abstract: A lithographic projection apparatus is disclosed in which measures are taken to prevent or reduce the presence of bubbles in liquid through which the projection beam radiates. This may be done, for example, by ensuring that a gap between a substrate and a substrate table is filled with immersion liquid or by causing a localized flow radially outwardly from the optical axis in the vicinity of the edge of the substrate.

Abstract: An immersion lithographic apparatus has adaptations to prevent or reduce bubble formation in one or more gaps in the substrate table by preventing bubbles escaping from the gap into the beam path and/or extracting bubbles that may form in the gap.

Abstract: An immersion lithographic apparatus is provided with a liquid confinement structure which defines at least in part a space configured to contain liquid between the projection system and the substrate. In order to reduce the crossing of the edge of the substrate which is being imaged (which can lead to inclusion of bubbles in the immersion liquid), the cross-sectional area of the space in a plane parallel to the substrate is made as small as possible. The smallest theoretical size is the size of the target portion which is imaged by the projection system. In an embodiment, the shape of a final element of the projection system is also changed to have a similar size and/or shape in a cross-section parallel to the substrate to that of the target portion.

Abstract: A lithographic apparatus is disclosed that has a semi-permeable membrane, a liquid inlet adapted to supply liquid to a first side of the membrane, and a gas inlet adapted to supply to a second side of the membrane either: (a) a vapor of the liquid, or (b) a gas which dissociates when dissolved in the liquid.

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: A lithographic apparatus is disclosed including a liquid supply system configured to at least partly fill a space between the projection system and the substrate with a liquid, an outlet configured to remove a mixture of liquid and gas passing through a gap between a liquid confinement structure of the liquid supply system and the substrate, and an evacuation system configured to draw the mixture through the outlet, the evacuation system having a separator tank arranged to separate liquid from gas in the mixture and a separator tank pressure controller, connected to a non-liquid-filled region of the separator tank, configured to maintain a stable pressure within the non-liquid-filled region.