Method for determining distortion and/or image surface

US7400388B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Wolfgang Emer · Aalen, DE
• Uwe Schellhorn · Aalen, DE
• Manfred Dahl · Lauchheim, DE
• Rainer Hoch · Aalen, DE

Key dates

• Filing date: May 27, 2005
• Grant date: Jul 15, 2008
• Expiry date: Mar 9, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70641
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method for determining at least one of distortion and de-focus for an optical imaging system. The method includes determining wavefront aberrations in a pupil plane of the optical imaging system by a wavefront measurement method, determining focus offset measured values in an xy-direction and/or z-direction for one or more different illumination settings by a test pattern measurement method with imaging and comparative evaluation of test patterns for the optical imaging system, and determining values for one or more aberration parameters that relate to the distortion and/or image surface from a prescribed relationship between the determined wavefront aberrations and the determined focus offset measured values. By prescribing a relationship between the wave aberrations and the focus offset measured values, it is possible for the results of the wavefront measurement method and of the test pattern measurement method to be linked to one another so as to enable an improved precision in the determination of distortion and/or image surface.