Patent ID: 8084896

Claim:
A system for positioning a workpiece, the system comprising: a monolithic stage configured to support the workpiece, the monolithic stage comprising a plurality of linear forcers; a ferromagnetic base plate positioned below the monolithic stage; an air bearing between the monolithic stage and the ferromagnetic base plate, the air bearing to provide a levitating force to the monolithic stage; a magnetic track coupled directly to the ferromagnetic base plate, the magnetic track creating a magnetic field, the linear forcers each operable to carry a current through the magnetic field created by the magnetic track, the currents generating forces to provide planar motion to the monolithic stage in three degrees of freedom; and at least one coil winding attached to the monolithic stage, the at least one coil winding to provide motion in at least a fourth degree of freedom using magnetic attraction with the ferromagnetic base plate.