METHOD OF MAKING HIGH PURITY OPTICAL FLUORIDE CRYSTALS

摘要

The present invention relates to the manufacturing of high purity optical flouride crystals, the making of purified optical flouride crystal feedstocks and to the anionic purification of optical fluoride crystalline materials. The invention relates generally to methods for removing oxide impurities from optical fluoride crystal feedstocks. More specifically, the invention relates to a method for preparing purified optical fluoride crystal feedstocks and the use of the feedstock in manufacturing VUV<200 nm transmission optical fluoride crystals for VUV lithography/laser systems.