Patent ID: 7642523
Filing Date: 2010-01-05
Classification: H01J

Abstract:
1. An apparatus for forming a vacuum chamber in which an object is placed, the apparatus comprising: a first reference member having a first reference surface defined thereon; a second reference member having a second reference surface defined thereon and substantially parallel with first reference surface; one or more main stages that move between the first and second reference surfaces, said one or more main stages having recessed pockets on both sides with conductance between them, at least one of the recessed pockets for holding the object; and a combination fluid and vacuum bearing, comprising a plurality of bearing lands and having a plurality of differentially pumped grooves on said both sides of the one or more main stages that permit motion of the stage between the reference surfaces and surround the bearing lands, thus forming the vacuum chamber between the reference surfaces; wherein the second reference member has an aperture defined therein, the aperture in the second reference member being open to the second reference surface and to one of the recessed pockets, for connection to a source of vacuum.