| 摘要 |
The present invention provides fluoride lens material crystals for VUV optical lithography systems and processes. The invention provides a fluoride optical lithography crystal for utilization in below 200 nm photolithography methods, for example 157 nm optical microlithography elements which manipulate below 193 nm optical lithography photons. The invention particularly pertains to mixed metal fluoride crystals; for example crystals comprised of an alkali metal fluoride and an alkaline earth metal fluoride; crystals comprised of a first alkaline metal fluoride and a second alkaline earth metal fluoride in which the two metals are different; and crystals comprised of an alkaline earth metal fluoride and lanthanum fluoride. |
