Catadioptric projection objective with geometric beam splitting

US7426082B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• David Shafer · Fairfield, US
• Alexander Epple · Aalen, DE
• Aurelian Dodoc · Heidenheim an der Brenz, DE
• Helmut Beierl · Heidenheim, DE
• Wilhelm Ulrich · Aalen, DE

Key dates

• Filing date: Nov 21, 2005
• Grant date: Sep 16, 2008
• Expiry date: Nov 21, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70966
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A projection exposure lens has an object plane, optical elements for separating beams, a concave mirror, an image plane, a first lens system arranged between the object plane and the optical elements for separating beams, a second double pass lens system arranged between the optical elements for separating beams and the concave mirror, a third lens system arranged between the optical elements for separating beams and the image plane. The second lens system has a maximum of five lenses.