Mirror for the EUV wavelength range, substrate for such a mirror, projection objective for microlithography comprising such a mirror or such a substrate, and projection exposure apparatus for microlithography comprising such a projection objective

US9494718B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Stephan Muellender · Aalen, DE
• Joern WEBER · Aalen, DE
• Wilfried Clauss · Lörrach, DE
• Hans-Jochen Paul · Aalen, DE
• Gerhard Braun · Judenhof, DE
• Sascha Migura · Aalen, DE
• Aurelian Dodoc · Heidenheim an der Brenz, DE
• Christoph Zaczek · Heubach, DE
• Gisela Von Blanckenhagen · Aalen, DE
• Roland Loercher · Aalen, DE

Key dates

• Filing date: Jun 15, 2012
• Grant date: Nov 15, 2016
• Expiry date: Apr 1, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70958
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A mirror (1a; 1a′; 1b; 1b′; 1c; 1c′) for the EUV wavelength range and having a substrate (S) and a layer arrangement, wherein the layer arrangement includes at least one surface layer system (P′″) consisting of a periodic sequence of at least two periods (P3) of individual layers, wherein the periods (P3) include two individual layers composed of different materials for a high refractive index layer (H′″) and a low refractive index layer (L′″), wherein the layer arrangement includes at least one surface protecting layer (SPL, Lp) or at least one surface protecting layer system (SPLS) having a thickness of greater than 20 nm, and preferably greater than 50 nm.