Lithography projection objective, and a method for correcting image defects of the same

US7463423B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Ulrich Loering · Schwäbisch Gmünd, DE
• Vladan Blahnik · Aalen, DE
• Wilhelm Ulrich · Aalen, DE
• Daniel Kraehmer · Aalen, DE
• Norbert Wabra · Werneck, DE

Key dates

• Filing date: Dec 13, 2007
• Grant date: Dec 9, 2008
• Expiry date: Dec 13, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/7015
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A lithography projection objective for imaging a pattern to be arranged in an object plane of the projection objective onto a substrate to be arranged in an image plane of the projection objective comprises a multiplicity of optical elements that are arranged along an optical axis of the projection objective. The optical elements comprise a first group, following the object plane, of optical elements, and a last optical element, which follows the first group and is next to the image plane and which defines an exit surface of the projection objective and is arranged at a working distance from the image plane. The projection objective is tunable or tuned with respect to aberrations for the case that the volume between the last optical element and the image plane is filled by an immersion medium with a refractive index substantially greater than 1. The position of the last optical element is adjustable in the direction of the optical axis. A positioning device is provided that positions at least the last optical element during immersion operation such that aberrations induced by disturbance are at least partially compensated.