Method of determining optical properties and projection exposure system comprising a wavefront detection system

US7230220B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Steffen Lauer · Aalen, DE
• Ulrich Wegmann · Oberkochen, DE
• Wolfgang Emer · Aalen, DE
• Harald Sakowski · Lauchheim, DE
• Martin Schriever · Aalen, DE

Key dates

• Filing date: Mar 24, 2006
• Grant date: Jun 12, 2007
• Expiry date: May 28, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70258
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method of determining at least one optical property of a projection exposure system is described, wherein the exposure system includes a beam delivery system having a light source for generating an exposure optical beam having light of a first wavelength (λ1) and a second wavelength (λ2), wherein a first ratio is defined as an intensity of light λ2 to an intensity of light λ1 in the exposure optical beam. The method includes supplying at least one measuring optical beam including light of at least λ1 to the projection optical system, detecting wavefronts having traversed the projection optical system, and determining an optical property in dependence of the detected wavefronts, wherein a second ratio of an intensity of light of λ2 to an intensity of light of λ1 in the measuring optical beam being incident on the detector of the wavefront detection system is less than the first ratio.