Protective layer on objective lens for liquid immersion lithography applications

摘要

Disclosed is an objective lens adapted for use in liquid immersion photolithography and a method for making such a lens. In one example, the objective lens has multiple lens elements, one of which includes a transparent substrate and a layer of protective coating (PC). The PC is formed proximate to the transparent substrate and is positioned between a liquid used during the liquid immersion photolithography and the transparent substrate to protect the transparent substrate from the liquid.