Projection exposure system for microlithography and method of monitoring a lateral imaging stability

US9720328B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Matthias Manger · Neukochen, DE
• Armin Rauthe-Schoech · Oberkochen, DE
• Ulrich Mueller · Hamburg, DE

Key dates

• Filing date: Jan 11, 2016
• Grant date: Aug 1, 2017
• Expiry date: Jan 11, 2036

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/7085
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A projection exposure system (10) for microlithography. The system includes projection optics (12) configured to image mask structures into a substrate plane (16), an input diffraction element (28) which is configured to convert irradiated measurement radiation (21) into at least two test waves (30) directed onto the projection optics (12) with differing propagation directions, a detection diffraction element (34; 28) which is disposed in the optical path of the test waves (30) after the latter have passed through the projection optics (12) and is configured to produce a detection beam (36) from the test waves (30) which has a mixture of radiation portions of both test waves (30), a photo detector (38) disposed in the optical path of the detection beam (36) which is configured to record the radiation intensity of the detection beam (36), time resolved, and an evaluation unit which is configured to determine the lateral imaging stability of the projection optics (12) from the radiation intensity recorded.