Patent ID: 6924882

Claim:
A lithographic projection apparatus comprising: a radiation system which supplies a projection beam of radiation; a first object table constructed and arranged to hold a mask; a second object table constructed and arranged to hold a substrate; an imaging projection system configured to image irradiated portions of the mask onto target portions of the substrate; first and second balance masses disposed along opposite sides of at least one of the object tables; and first and second motors configured to move the at least one of the object tables, each motor having two cooperating electromagnetic members, a first of the members being operatively associated with the at least one of the object tables and a second of the members being operatively associated with at least one of the first and second balance masses, wherein said first and second balance masses are substantially free to move in at least a first direction to provide balancing to the at least one of the object tables, and wherein the at least one of the object tables is supported by a support structure that is substantially independent from the first and second balance masses.