Projection objective for immersion lithography

US7460206B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Patrick Scheible · Aalen, DE
• Alexander Hirnet · Oberkochen, DE
• Alexandra Pazidis · Aalen, DE
• Karl-Heinz Schuster · Oberkochen, DE
• Christoph Zaczek · Heubach, DE
• Michael Lill · Kaiserslautern, DE
• Harald Schink · Aalen, DE
• Markus Brotsack · Aalen, DE
• Ulrich Loering · Schwäbisch Gmünd, DE
• Toralf Gruner · Hennef (Sieg), DE
• Karl-Stefan Weissenrieder · Langenau, DE

Key dates

• Filing date: Dec 20, 2004
• Grant date: Dec 2, 2008
• Expiry date: Apr 24, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70341
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

In a projection objective provided for imaging a pattern arranged in an object plane of the projection objective into an image plane of the projection objective with the aid of an immersion medium arranged between a last optical element of the projection objective in the light path and the image plane, the last optical element has a transparent substrate and a protective layer system that is fitted to the substrate, is provided for contact with the immersion medium and serves for increasing the resistance of the last optical element to degradation caused by the immersion medium.