Metrology system having an EUV optical unit

US10948637B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Dirk Hellweg · Langenau, DE
• Stefan Mueller · Villingen, DE
• Ralf Gehrke · Aalen, DE

Key dates

• Filing date: Jul 3, 2018
• Grant date: Mar 16, 2021
• Expiry date: Feb 19, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70625
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An EUV greyscale filter of an EUV optical unit of a metrology system has a membrane that is at least partly transmissive in regions for EUV light in the wavelength range of between 5 nm and 30 nm. The latter interacts with a whole beam of the EUV light in the operational position of the EUV greyscale filter. This results in a metrology system with extended application possibilities on account of the EUV greyscale filter.