Projection objective having a high aperture and a planar end surface

US7466489B2 · kind B2 · utility

Inventors

• Susanne Beder · Aalen, DE
• Wolfgang Singer · Aalen, DE
• Karl-Heinz Schuster · Oberkochen, DE

Key dates

• Filing date: Jun 14, 2005
• Grant date: Dec 16, 2008
• Expiry date: Jul 2, 2025

Classification

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

Abstract

A projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective suitable for microlithography projection exposure machines has a plurality of optical elements transparent for radiation at an operating wavelength of the projection objective. At least one optical element is a high-index optical element made from a high-index material with a refractive index n≧1.6 at the operating wavelength.