Patent ID: 8587766

Claim:
A lithographic projection apparatus having an illumination system comprising: an array of reflective elements configured to define an intensity distribution of a radiation beam in accordance with an illumination mode; a polarization member positioned or positionable at various positions before the array of reflective elements in a path of the beam, the polarization member configured to provide a polarization to the beam of radiation and movable relative to the reflective elements through at least part of the beam path so that, at each of said various positions, said polarization member is traversable by a section area of the beam of a different dimension that is less than an entire cross-section of the beam to polarize said section area with said polarization; a support structure configured to support a patterning device, the patterning device configured to pattern the beam according to a desired pattern; a substrate table configured to hold a substrate; and a projection system configured to project the patterned beam onto a target portion of the substrate.