INTRINSIC BIREFRINGENCE COMPENSATION FOR BELOW 200 NANOMETER WAVELENGTH OPTICAL LITHOGRAPHY COMPONENTS WITH CUBIC CRYSTALLINE STRUCTURES

摘要

Stress-induced photoelastic birefringence compensates for intrinsic birefringence of cubic crystalline structures (12) in deep ultraviolet (less than 200 nm) microlithographic imaging systems (10). Both the photoelastic birefringence and the intrinsic birefringence are expressed in a tensor format simplified by the symmetries of cubic crystalline structures. The stress-induced photoelastic birefringence can be sized to individually compensate for intrinsic birefringence exhibited in the same optical elements or preferably to collectively compensate for the cumulative effects of intrinsic birefringence in other optical elements in the lithography system.