The invention is directed to elements used in high power laser
lithographic systems operating at below 250 nm, and in particular to
elements that have a coating of selected materials to extend lifetime of
the elements; and to a method of preparing the extended lifetime
elements. The invention is particularly directed to gratings and mirrors
that are coated with silicon dioxide, aluminum oxide or fluorinated
silicon dioxide. The coatings of the invention attain their extended life
as a result of being deposited while being simultaneously bombarded with
an energetic ion plasma.