The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of utmost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multiplayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.
Proceedings Title: Emerging Lithographic Technologies, Conference | 7th | Emerging Lithographic Technologies VII | SPIE
Conference Dates: February 1, 2003
Conference Title: Proceedings of SPIE--the International Society for Optical Engineering
Pub Type: Conferences
capping layer, extreme ultraviolet (EUV) lithography, multilayers, optics, oxidation resistance, reflectivity, ruthenium