Patent ID: 8717536

Claim:
A lithographic apparatus, comprising: an illumination system configured to condition a radiation beam; a support configured to support a patterning device, the patterning device being configured to impart the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table configured to hold a substrate; a projection system configured to project the patterned radiation beam onto a target portion of the substrate to form a projected image of the pattern; and a control system configured to dynamically control movements of one or more optical elements within the projection system during a scanning operation, wherein the scanning operation comprises the patterning device and the substrate being scanned synchronously through the radiation beam to apply the pattern to a desired portion on the substrate, and wherein the dynamically controlled movements provide corrective variations in one or more properties of the projection system during the scanning operation to compensate for distortion effects that vary in the projected image on the target portion of the substrate during the scanning operation.