Optical element unit for exposure processes

US7545483B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Bernhard Gellrich · Aalen, DE
• Jens Kugler · Heubach, DE
• Thomas Schletterer · Oberkochen, DE
• Guido Limbach · Aalen, DE
• Julian Kaller · Oberkochen, DE
• Hans-Juergen Scherle · Aalen, DE
• Detlev Mueller · Ellwangen, DE
• Dieter Schmerek · Hennef (Sieg), DE

Key dates

• Filing date: Jan 15, 2008
• Grant date: Jun 9, 2009
• Expiry date: Jan 15, 2028

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70933
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical element unit is provided comprising an optical element group; a housing receiving said optical element group and having an inner housing part and an exit end; and a purge unit connected to said housing and providing a purge medium to said inner housing part. The optical element group comprises an ultimate optical element. The ultimate optical element is located at the exit end of housing and separates the inner housing part from an environment external to the housing. The ultimate optical element and the housing define a sealing gap. The purge unit provides purge medium to the sealing gap to prevent intrusion of contaminants into the inner housing part.