title: Spectral-purity-enhancing layer for multilayer mirrors.
abstract: We demonstrate, both theoretically and experimentally, that special spectral-purity-enhancing multilayer mirror systems can be designed and fabricated to substantially reduce the level of out-of-band radiation expected in an extreme ultraviolet lithographic tool. A first proof of principle of applying such spectral-purity-enhancement layers showed reduced out-of-band reflectance by a factor of five, while the in-band reflectance is only 4.5% (absolute) less than for a standard capped multilayer.
authors.affiliation: Philips Research Laboratories, Eindhoven, The Netherlands. maarten.van.herpen@philips.com
authors.forename: M M J W
authors.initials: MM
authors.lastname: van Herpen
authors.forename: R W E
authors.initials: RW
authors.lastname: van de Kruijs
authors.forename: D J W
authors.initials: DJ
authors.lastname: Klunder
authors.forename: E
authors.initials: E
authors.lastname: Louis
authors.forename: A E
authors.initials: AE
authors.lastname: Yakshin
authors.forename: S Alonso
authors.initials: SA
authors.lastname: van der Westen
authors.forename: F
authors.initials: F
authors.lastname: Bijkerk
authors.forename: V
authors.initials: V
authors.lastname: Banine