Patent ID: 7034920

Claim:
A lithographic projection apparatus comprising: a projection beam illumination system which supplies a projection beam of radiation; a first object table which holds a projection beam patterning device which patterns the projection beam according to a desired pattern; a second object table which holds a substrate; a projection system which images the patterned beam onto a target portion of the substrate; and a balanced positioning module constructed and arranged to position at least one of said object tables in at least three degrees of freedom, the positioning module comprising: a balance frame disposed above a guide surface; a bearing which movably supports said balance frame on said guide surface; a positioning system disposed within or upon said balancing frame, said positioning system being free to move in at least a first direction and a second direction which are orthogonal to each other, and to rotate around an axis perpendicular to a plane defined by said first and second directions, wherein said positioning system is arranged such that a reaction force acting in opposition to a drive force exerted on said object table is transmitted to said balance frame.