Antireflection coating for ultraviolet light

US6825976B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Hans-Jochen Paul · Aalen, DE
• Matthias Heller · Hohenahr, DE

Key dates

• Filing date: Jan 7, 2002
• Grant date: Nov 30, 2004
• Expiry date: Jan 7, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B1/115
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical component with a low reflectance for ultraviolet light in a wavelength range between approx. 180 nm and approx. 370 nm, in particular approx. 248 nm, and for a high angle of incidence up to at least approx. 40° has a substrate and a multilayer antireflection system arranged on at least one surface of said substrate to provide reflection reduction. The multilayer system distinguishes itself in that the layer adjacent to the substrate does not consist of magnesium fluoride and that none of the layers has a thickness of more than half of the working wavelength. In particular, the layer thicknesses of the low refractive materials should not exceed ⅓ the working wavelength. By adhering to these boundary conditions, antireflective coatings can be produced that provide both permanent laser resistance as well as a high resistance against inner layer stress and thermal stress.