EUV mirror and optical system comprising EUV mirror

US10203435B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Thomas Schicketanz · Aalen, DE
• Oliver Dier · Lauchheim, DE
• Sebastian Strobel · Aalen, DE
• Ralf Winter · Tegernsee, DE

Key dates

• Filing date: Jul 20, 2016
• Grant date: Feb 12, 2019
• Expiry date: Feb 17, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G21K1/062
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An EUV mirror has a multilayer arrangement applied on a substrate. The multilayer arrangement includes a first layer group having ten or more first layer pairs. Each first layer pair has a first layer composed of a high refractive index first layer material having a first layer thickness, has a second layer composed of a low refractive index second layer material having a second layer thickness and has a period thickness corresponding to the sum of the layer thicknesses of all the layers of a first layer pair. The layer thicknesses of one of the layer materials are defined, depending on the period number, by a simply monotonic first layer thickness profile function, e.g. by a linear, quadratic or exponential layer thickness profile function. The layer thicknesses of the other of the layer materials vary, depending on the period number, in accordance with a second layer thickness profile function.