Patent ID: 7830495

Claim:
A lithographic apparatus, comprising: an illumination system configured to condition a radiation beam; a patterning device support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its 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; a motor comprising a stationary magnet assembly having a two dimensional arrangement of alternately polarized magnets to generate a spatially alternately polarized magnetic field, the motor configured to drive the patterning device support or the substrate support; and a position sensor configured to measure a position of the patterning device support or the substrate support, the position sensor comprising a magnetic field sensor configured to perform a quadrature measurement of a field strength of the magnetic field in a plane, and a sensor processing device configured to determine the position from the quadrature measurement.