Patent · US Active

Optical system for radiation in the EUV-wavelength range and method for measuring a contamination status of EUV-reflective elements

US7763870B2 · kind B2 · utility

1Cited by

7References

18Claims

0Family size

Assignees

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

Inventors

Dirk Heinrich Ehm · Beckingen, DE
Hermann Bieg · Wertingen, DE
Hans-Juergen Mann · Oberkochen, DE
Stephan Muellender · Aalen, DE
Johannes Hubertus Josephina Moors · Roosteren, NL
Bastiaan Theodoor Wolschrijn · Abcoude, NL

Key dates

Filing date	Sep 14, 2007
Grant date	Jul 27, 2010
Priority date	—
Expiry date	Sep 8, 2028

Classification

Technology area (CPC G)Physics
CPC primaryG03F7/70941
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An optical system for radiation in the EUV wavelength range, in particular a projection exposure apparatus, having at least one vacuum vessel, including: at least one EUV-reflective optical element arranged in an optical path, and a holder which includes at least one sample element, the sample element having an optical surface which is exposed to incident EUV-radiation outside of the optical path, the sample element being sensitive to chemical alterations under influence of the incident EUV-radiation which also affect the optical element. The optical system further includes at least one detection unit for online detection of the contamination status of the sample element during exposure of the sample element to the incident EUV-radiation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.