Reticular objective for microlithography-projection exposure installations

US6366410B1 · kind B1 · utility

Assignee

• Carl Zeiss Stiftung · DE

Inventors

• Jorg Schultz · Aalen, DE
• Johannes Wangler · Oberkochen, DE
• Karl-Heinz Schuster · Oberkochen, DE

Key dates

• Filing date: Aug 12, 1999
• Grant date: Apr 2, 2002
• Expiry date: Aug 12, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70225
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A REMA objective is realized by introduction of a few (1 to 5 units) aspherical surfaces of high-quality correction with a low number of lenses (no more than 10), and low path in glass (maximum 25% to 30%) of the object-reticle distance, thus enhancing efficiency.