Illumination system, lithographic apparatus, mirror, method of removing contamination from a mirror and device manufacturing method
US7875863B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 2006 |
| Grant date | Jan 25, 2011 |
| Priority date | — |
| Expiry date | Nov 25, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG21K2201/067
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An EUV illumination system, for example, for use in a photolithographic apparatus is configured to condition a radiation beam. A hydrogen radical source configured to supply gas containing hydrogen or hydrogen radicals into the illumination system. The hydrogen gas is effective to remove carbonaceous contamination from the surface of a mirror in the illumination system or to form a buffer against unwanted gases. In order to prevent damage by hydrogen that penetrates the mirror, the mirror comprises a layer made of metal non-metal compound adjacent a reflection surface of the mirror. A transition metal carbide, nitride, boride or silicide compound or mixture thereof may be used for example.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.