Method of measuring a deviation of an optical surface from a target shape using interferometric measurement results

US8508749B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Ralf Arnold · Aalen, DE
• Stefan Schulte · Marburg, DE
• Bernd Doerband · Aalen, DE

Key dates

• Filing date: Sep 10, 2012
• Grant date: Aug 13, 2013
• Expiry date: Sep 10, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49771
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method of measuring a deviation of an optical surface from a target shape and a method of manufacturing an optical element. This method of measuring the deviation includes: performing a first interferometric measurement using a first diffractive measurement structure, which is arranged to cover a first area of the optical surface, to provide a first interferometric measurement result, performing a second interferometric measurement using a second diffractive measurement structure, which is arranged to cover a second area of the optical surface different from the first area, to provide a second interferometric measurement result, and determining a deviation of the optical surface from the target shape.