Catadioptric reduction lens

US7006304B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Alexander Epple · Aalen, DE
• Helmut Beierl · Heidenheim, DE

Key dates

• Filing date: Feb 6, 2004
• Grant date: Feb 28, 2006
• Expiry date: Feb 6, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70275
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A catadioptric projection lens configured for imaging a pattern arranged in an object plane (2) onto an image plane (4) while creating a single, real, intermediate image (3) has a catadioptric imaging group (5) having a concave mirror (6) and a beam-deflector (7), and a dioptric imaging lens group (20) that commences after the beam-deflector. The system is configured such that the intermediate image follows the first lens (17) of a dioptric section (8) and is preferably readily accessible. Arranging the intermediate image both between a pair of lenses (17, 21) of the dioptric section and at a large distance behind the final reflective surface of the beam-deflector helps to avoid imaging aberrations.