Method of operating a projection exposure tool for microlithography

US9442381B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Olaf Conradi · Sonthofen, DE
• Michael Totzeck · Schwäbisch Gmünd, DE
• Ulrich Loering · Schwäbisch Gmünd, DE
• Dirk Juergens · Munich, DE
• Ralf Mueller · Germersheim, DE
• Christian Wald · Munich, DE

Key dates

• Filing date: Jul 11, 2013
• Grant date: Sep 13, 2016
• Expiry date: Aug 13, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/708
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method of operating a projection exposure tool for microlithography is provided. The projection exposure tool has a projection objective for imaging object structures on a mask into an image plane using electromagnetic radiation, during which imaging the electromagnetic radiation causes a change in optical properties of the projection objective. The method comprises the steps of: providing the layout of the object structures on the mask to be imaged and classifying the object structures according to their type of structure, calculating the change in the optical properties of the projection objective effected during the imaging process on the basis of the classification of the object structures, and using the projection exposure tool for imaging the object structures into the image plane, wherein the imaging behavior of the projection exposure tool is adjusted on the basis of the calculated change of the optical properties in order to at least partly compensate for the change of the optical properties of the projection objective caused by the electromagnetic radiation during the imaging process.