Projection exposure apparatus for microlithography comprising an optical distance measurement system

US9714822B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Alexander Wolf · Oberkochen, DE
• Markus Schwab · Aalen, DE
• Toralf Gruner · Hennef (Sieg), DE
• Joachim Hartjes · Aalen, DE

Key dates

• Filing date: Jan 16, 2015
• Grant date: Jul 25, 2017
• Expiry date: Jan 16, 2035

Classification

• Technology area (CPC —): General

Abstract

A projection exposure apparatus (10) for microlithography has a plurality of optical components (M1-M6) forming an exposure beam path, as well as a distance measurement system (30, 130, 230) configured to measure a distance between at least one of the optical components and a reference element (40, 140, 240). The distance measurement system comprises a frequency comb generator (32, 132, 232), which is configured to generate electromagnetic radiation (36, 236) having a comb-shaped frequency spectrum.