Method for making optical elements for microlithography, the lens systems obtained by the method and their uses

US7679806B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Gunther Wehrhan · Jena, DE
• Regina Martin · Jena, DE
• Lutz Parthier · Kleinmachnow, DE
• Joerg Staeblein · Jena, DE
• Martin Letz · Mainz, DE
• Jochen Alkemper · Klein-Winternheim, DE
• Konrad Knapp · Mainz, DE
• Klaus Petermann · Wedel, DE

Key dates

• Filing date: Mar 7, 2006
• Grant date: Mar 16, 2010
• Expiry date: Jan 12, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70958
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The optical elements for ultraviolet radiation, especially for microlithography, are made from cubic granet, cubic spinel, cubic perovskite and/or cubic M(II)- as well as M(IV)-oxides. The optical elements are made from suitable crystals of Y3Al5O12, Lu3Al5O12, Ca3Al2Si3O12, K2NaAlF6, K2NaScF6, K2LiAlF6 and/or Na3Al2Li3F12, (Mg, Zn)Al2O4, CaAl2O4, CaB2O4 and/or LiAl5O8, BaZrO3 and/or CaCeO3. A front lens used in immersion optics for microlithography at wavelengths under 200 nm is an example of a preferred optical element of the present invention.