Optical component and method of inducing a desired alteration of an optical property therein

US6728021B1 · kind B1 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Alexander Kohl · Aalen, DE
• Hubert Holderer · Oberkochen, DE

Key dates

• Filing date: Nov 18, 2002
• Grant date: Apr 27, 2004
• Expiry date: Nov 18, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70966
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

High precision optical components, for example CaF2 lenses in lithographic systems for the production of integrated circuits, often suffer from stress induced birefringence and other imperfections. For altering the optical properties in a confined region of the optical component, the latter is exposed to a beam of ions having an energy preferably in the order 100 MeV/u. This results in a modification of the optical properties due to an interaction of the ions with the surrounding medium the optical component consists of. By carefully choosing the parameters of the process, it is possible to alter the refractive index or the mechanical stress distribution or other optical properties within a confined region of this medium.