Abstract: An apparatus, which may form part of a lithographic apparatus, comprises a substrate table, a projection system, a gas lock and a gas flow guide. The substrate table is suitable for supporting a substrate. The projection system has a body which defines an interior and an opening. The projection system is configured and arranged to project a radiation beam through the opening onto a substrate supported by the substrate table. The gas lock is suitable for providing a gas flow from the opening away from the interior. The gas flow guide is configured to guide at least a portion of the gas flow away from the substrate supported by the substrate table.

Abstract: A patterning device cooling system for thermally conditioning a patterning device of a lithographic apparatus, wherein the patterning device in use, is being irradiated by exposure radiation, wherein the patterning device cooling system comprises: a thermal conditioner configured to thermally condition the patterning device; and a controller configured to control the thermal conditioner to thermally condition the patterning device dependent on an amount of the exposure radiation absorbed by the patterning device.

Abstract: A method of processing a substrate includes: providing a substrate with a layer of photosensitive material on a surface of the substrate; and removing at least part of the photosensitive material from around an outer edge of the layer of photosensitive material so as to generate an edge, having a radial width, around the layer of photosensitive material remaining on the surface of the substrate, wherein the photosensitive material varies in thickness forming a thickness profile across the radial width and the removing is controlled so as to generate variation in the thickness profile along the length of the edge, and/or wherein the removing is controlled so as to generate a rough edge around the layer of photosensitive material remaining on the surface of the substrate.

Abstract: A method of performing a lithographic exposure of a substrate, the substrate being held on a substrate table, the substrate table comprising a cooling system operative to cool the substrate table, the method comprising performing an alignment measurement of the substrate, applying heat to the substrate table to reduce cooling of the substrate table provided by the cooling system, the heat being applied between a time at which the alignment measurement is performed and a time at which the lithographic exposure is performed and performing the lithographic exposure of the substrate.

Abstract: A patterning apparatus for a lithographic apparatus, the patterning apparatus including a patterning device support structure configured to support a patterning device having a planar surface; a patterning device conditioning system including a first gas outlet configured to provide a first gas flow over the planar surface in use and a second gas outlet configured to provide a second gas flow over the planar surface in use, wherein the first gas outlet and the second gas outlet are arranged at different distances perpendicular to the planar surface; and a control system configured to independently control a first momentum of gas exiting the first gas outlet and a second momentum of gas exiting the second gas outlet or to independently vary the first gas flow and/or the second gas flow over the planar surface of the patterning device.

Abstract: A patterning device cooling system for thermally conditioning a patterning device of a lithographic apparatus, wherein the patterning device in use, is being irradiated by exposure radiation, wherein the patterning device cooling system has: a thermal conditioner configured to thermally condition the patterning device; and a controller configured to control the thermal conditioner to thermally condition the patterning device dependent on an amount of the exposure radiation absorbed by the patterning device.