Patent ID: 8797503

Claim:
A lithographic projection apparatus, comprising: a support structure to hold a patterning device, the patterning device configured to provide a patterned beam of radiation; a movable table; a projection system to project the patterned beam onto a target portion of a radiation-sensitive substrate; and a liquid supply system to provide a liquid to a space between the table and an optical element, nearest the table, of the projection system and to contact a surface, nearest the table, of the optical element, the liquid supply system comprising a liquid confinement structure extending along at least a part of a boundary of the space between the optical element surface and the table, wherein: at least part of the liquid confinement structure is positioned between the optical element surface and the table, the table being movable with respect to the at least part of the liquid confinement structure, the at least part of the liquid confinement structure has an aperture through which the patterned beam can pass, the aperture having a cross-sectional area smaller than the area of the substrate, the liquid confinement structure comprises an inlet to supply the liquid to the space above the aperture, and the liquid confinement structure comprises an outlet to remove the liquid, supplied by the inlet, from the space below the aperture.