Method for avoiding a degradation of an optical element, projection system, illumination system and projection exposure apparatus

US12140877B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Dirk Heinrich Ehm · Beckingen, DE
• Wilbert KRUITHOF · Pleinfeld, DE
• Timo Laufer · Stuttgart, DE

Key dates

• Filing date: Jun 6, 2022
• Grant date: Nov 12, 2024
• Expiry date: Jul 20, 2043

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70925
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Method for avoiding a degradation of an optical element, wherein the optical element is arranged in a housing, comprising: a) determining a first degradation value; b) determining a second degradation value, wherein the first degradation value and the second degradation value are determined at different times; c) forming a degradation profile based on the first degradation value and the second degradation value; d) calculating a temporal development of the degradation profile; e) determining at least one predicted degradation value based on the calculated temporal development of the degradation profile; f) comparing the at least one predicted degradation value with a predefinable first limit degradation value; g) monitoring for a predefinable first deviation between the at least one predicted degradation value and the first limit degradation value; h) feeding a first decontamination medium into the interior if attainment of the predefinable first deviation is identified.