Patent ID: 7710540

Claim:
A lithographic apparatus comprising: an illumination system configured to condition a radiation beam; a patterning device capable of imparting the radiation beam with a pattern in said radiation beam cross-section to form a patterned radiation beam; a substrate support constructed to hold a substrate; a projection system configured to project the patterned radiation beam onto a target portion of the substrate; and a position control system configured to control a position of the target portion of the substrate, the position control system comprising a position measurement system configured to determine a position of a sensor or sensor target on the substrate support, a controller configured to provide a control signal based on a desired position of the target portion and the determined position; and one or more actuators configured to act on the substrate support, wherein the position control system comprises a stiffness compensation model of the substrate support, the stiffness compensation model comprising a relation between a force exerted on the substrate support and a resulting position error of the target portion, the resulting position error of the target portion corresponding to a difference of change in position between the target portion and the sensor or sensor target resulting from the exerted force on the substrate support, the position control system configured to substantially correct at least during projection of the patterned radiation beam on the target portion, the position of the target portion using the stiffness compensation model.