Patent ID: 6906786
Filing Date: 2005-06-14
Classification: B23Q,G03F

Abstract:
1. A lithographic projection apparatus, comprising: a radiation system constructed and arranged to provide a beam of radiation; a support constructed and arranged to support a patterning device, the patterning device constructed and arranged to pattern the beam of radiation according to a desired pattern; a substrate table constructed and arranged to hold a substrate; a projection system constructed and arranged to project the patterned beam of radiation onto a target portion of the substrate; a base frame; a balance mass; and a positioning actuator, connected between the substrate table or the support and the balance mass, constructed and arranged to generate a reaction force between the balance mass and the substrate table or the support thereby to position the substrate table or the support relative to the projection system, wherein the balance mass is coupled to the base frame via an elastic coupling so that the balance mass has a suspension eigenfrequency of between 0.3 and 10 Hz such that a portion of the reaction force is exerted on the base frame.