Lithographic apparatus, device manufacturing method, and device manufactured thereby

摘要

A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.