Photolithographic method and UV transmitting fluoride crystals with minimized spatial dispersion

摘要

The invention provides a UV below 200 mm lithography method. The invention includes providing a below 200 mm radiation source for producing <200-nm light, providing a plurality of mixed cubic flouride crystal optical elements, with the fluoride crystals comprised of a combination of alkaline earth cations having different optical polarizabilities such as to produce an overall isotropic polarizability which minimizes the fluoride crystal spatial dispersion below 200 nm, transmitting <200-nm light through the cubic fluoride crystal optical elements, forming a lithography pattern with the light, reducing the litographic patter and projecting the lithography pattern with the cubic fluoride crystal optical elements onto a UV radiation sensitive lithography printing medium to form a printed lithographic pattern. The invention includes making the mixed fluoride crystals and forming optical element thereform.