Optical element for UV or EUV lithography with coatings having optimized stress and thickness

US8848167B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Johannes Lippert · Buch am Wald, DE
• Dirk Schaffer · Jena, DE

Key dates

• Filing date: Aug 12, 2011
• Grant date: Sep 30, 2014
• Expiry date: May 15, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70316
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

To reduce deformations which may be caused by a functional coating on a substrate in an optical element for UV or EUV lithography, an optical element is suggested comprising a functional coating (46) on a first surface (42) of a substrate (41), wherein the substrate (41) comprises a second surface (43) having a common edge (45) with the first surface (42), and the second surface (43) also has a coating (47) and the thickness t2 and the stress σ2 of the coating (47) on the second surface (33, 43) are chosen such that, in combination with the thickness t1 and the stress σ1 of the functional coating (36, 46) on the first surface (32, 42), the conditionis fulfilled, wherein X has a value between 0.8 and 5.0.