Patent ID: 7522261
Filing Date: 2009-04-21
Classification: G03F

Abstract:
1. A lithographic projection apparatus arranged to project a patterned beam of radiation from a patterning device, through a liquid, onto a substrate, the apparatus comprising: a projection system configured to project the patterned beam of radiation onto the substrate; and a liquid confinement structure configured to at least partly confine the liquid to a space between the projection system and the substrate, wherein the confinement structure has a buffer surface positioned, when in use, in close proximity to a plane substantially comprising the upper surface of the substrate and of a substrate table configured to hold the substrate, to define a passage having a flow resistance, the buffer surface comprising a recess, said recess when in use, being normally full of liquid to enable rapid filling of a gap between the substrate and the substrate table as the gap moves under the buffer surface, wherein the recess has a volume that is substantially equal to a volume of the gap.