Lithography masks and methods of manufacture thereof are disclosed. A preferred embodiment comprises a method of manufacturing a lithography mask. The method includes providing a substrate, forming a first pattern in a first region of the substrate, and forming a second pattern in a second region of the substrate, the second pattern comprising patterns for features oriented differently than patterns for features of the first pattern. The method includes affecting a polarization rotation of light differently in the first region than in the second region of the substrate.