Optical arrangement, in particular projection exposure apparatus for EUV lithography, as well as reflective optical element with reduced contamination

US8585224B2 · kind B2 · utility

Assignees

• Carl Zeiss SMT GmbH · DE
• ASML NETHERLANDS B.V. · NL

Inventors

• Dirk Heinrich Ehm · Beckingen, DE
• Stephan Muellender · Aalen, DE
• Thomas Stein · Oberkochen, DE
• Johannes Hubertus Josephina Moors · Roosteren, NL
• Bastiaan Theodoor Wolschrijn · Abcoude, NL
• Dieter Kraus · Munich, DE
• Richard Versluis · Delft, NL
• Marcus Gerhardus Hendrikus Meijerink · The Hague, NL

Key dates

• Filing date: Feb 10, 2013
• Grant date: Nov 19, 2013
• Expiry date: Feb 10, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G21K2201/061
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical arrangement, e.g. a projection exposure apparatus (1) for EUV lithography, includes: a housing (2) enclosing an interior space (15); at least one, preferably reflective optical element (4-10, 12, 14.1-14.6) arranged in the housing (2); at least one vacuum generating unit (3) for the interior space (15) of the housing (2); and at least one vacuum housing (18, 18.1-18.10) arranged in the interior space (15) and enclosing at least the optical surface (17, 17.1, 17.2) of the optical element (4-10, 12, 14.1-14.5). A contamination reduction unit is associated with the vacuum housing (18.1-18.10) and reduces the partial pressure of contaminating substances, in particular of water and/or hydrocarbons, at least in close proximity to the optical surface (17, 17.1, 17.2) in relation to the partial pressure of the contaminating substances in the interior space (15).