Patent ID: 8755030

Claim:
A lithographic apparatus comprising: a support constructed to support a patterning device, the patterning device being capable of imparting a radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table constructed to hold a substrate; a projection system configured to project the patterned radiation beam onto a target portion of the substrate, wherein the projection system includes an optical element that is adjustable, an actuator configured to exert a torque or force on the patterning device, and a controller, the controller being connected to the actuator and to the adjustable optical element, the controller being arranged to drive the actuator to exert a torque or force on the patterning device to apply a desired bending moment to the patterning device, the desired bending moment applied to at least partly compensate a field curvature error of the projection system and imparting a bending to the patterning device, and drive the adjustable optical element in accordance with the bending of the patterning device resulting from the applied desired bending moment, wherein the controller is arranged to drive the adjustable optical element to at least partly compensate for a magnification resulting from the desired bending moment applied to the patterning device.