Projection lens for EUV microlithography, film element and method for producing a projection lens comprising a film element

US10001631B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Boris Bittner · Roth, DE
• Norbert Wabra · Werneck, DE
• Sonja Schneider · Lehrberg, DE
• Ricarda Schoemer · Zusmarshausen, DE
• Hendrik Wagner · Bielefeld, DE
• Christian Wald · Munich, DE
• Rumen Iliew · Oberkochen, DE
• Thomas Schicketanz · Aalen, DE
• Toralf Gruner · Hennef (Sieg), DE
• Walter Pauls · Wertingen, DE
• Holger Schmidt · Wuppertal, DE
• Matthias Roesch · Aalen, DE

Key dates

• Filing date: Aug 8, 2014
• Grant date: Jun 19, 2018
• Expiry date: Jan 29, 2035

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49826
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A film element of an EUV-transmitting wavefront correction device is arranged in a beam path and includes a first layer of first layer material having a first complex refractive index n1=(1−δ1)+iß1, with a first optical layer thickness, which varies locally over the used region in accordance with a first layer thickness profile, and a second layer of second layer material having a second complex refractive index n2=(1−δ2)+iß2, with a second optical layer thickness, which varies locally over the used region in accordance with a second layer thickness profile. The first and second layer thickness profiles differ. The deviation δ1 of the real part of the first refractive index from 1 is large relative to the absorption coefficient ß1 of the first layer material and the deviation δ2 of the real part of the second refractive index from 1 is small relative to the absorption coefficient ß2 of the second layer material.