Patent ID: 6445440
Filing Date: 2002-09-03
Classification: G03F

Abstract:
A lithographic projection apparatus, comprising:a radiation system constructed to supply a projection beam of radiation; a first object table provided with a mask holder for holding a mask; a second object table provided with a substrate holder for holding a substrate; a projection system constructed and arranged to image an irradiated portion of the mask onto a target portion of the substrate; a vacuum chamber having a wall enclosing at least one of said first and second object tables, said vacuum chamber wall having an aperture therein; a sliding seal constructed and arranged to seal said aperture and being displaceable in at least one direction parallel to said vacuum chamber wall through a predetermined range of movement whilst maintaining the seal of said aperture; a mechanical linkage constructed and arranged to transmit displacement of said sliding seal to the object table within said vacuum chamber to cause corresponding movement thereof; and a seal positioning assembly constructed and arranged to displace said sliding seal, thereby to displace said object table within said vacuum chamber.