System for flushing at least one internal space of an objective

US6825914B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Joachim Schroeder · Stuttgart, DE
• Gerald Richter · Aachen, DE
• Dieter Schmerek · Hennef (Sieg), DE
• Uwe Schubert · Aalen, DE
• Maria Johanna Agnes Rubingh · Eindhoven, NL
• Willem Van Schaik · 's-Hertogenbosch, NL
• Siebe Landheer · Eindhoven, NL

Key dates

• Filing date: Dec 7, 2001
• Grant date: Nov 30, 2004
• Expiry date: Dec 7, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70883
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

In a system for flushing at least one internal space of an objective, in particular an exposure projection objective for semiconductor lithography, flushing is performed by mixing at least two inert gasses in such a way that the refractive index resulting therefrom corresponds at least approximately to the refractive index of air.