Patent ID: 6970232

Claim:
A photolithography tool comprising: condenser optics positioned to receive light from a light source, said condenser optics positioned to direct an optical beam formed from said light through a reticle; and projection optics configured to form an image of said reticle onto a substrate, said projection optics including: one or more cubic crystalline lens elements receiving said directed optical beam propagated through said reticle, said one or more cubic crystalline lens elements having intrinsic birefringence which introduces retardance into said optical beam, and polarization rotation optics comprising a circular retarder having orthogonal circular eigenpolarization states with about Â±90(2n+1) degrees phase delay between the two orthogonal circular eigenpolarization states, where n is an integer, said polarization rotation optics positioned along a common optical pathway with said reticle and said one or more cubic crystalline lens elements, the polarization rotation optics rotating the polarization of said optical beam transmitted through said one or more cubic crystalline lens elements.