Carl Zeiss Smt Gmbh

Joachim Kalden

Stig Bieling

An illumination optical unit for EUV projection lithography includes a field facet mirror with a plurality of field facets for guiding illumination light into an object field where a lithography mask is arrangeable. At least one spectral output coupling mirror section is arranged on the field facet mirror. The mirror section serves to output couple the spectral analysis partial beam from a beam path of the illumination light. A detector serves for the spectral analysis of the spectral analysis partial beam. This can yield an illumination optical unit in which process monitoring during the projection exposure is improved.

Illumination optical system for EUV projection lithography

A method for correcting a reflective optical element for the wavelength range between 5 nm and 20 nm, which includes a multilayer system on a substrate. The multilayer system has layers consisting of at least two alternately arranged different materials with a different real component of the refractive index for a wavelength in the extreme ultraviolet wavelength range. The method includes: measuring the reflectivity distribution over the surface of the multilayer system; comparing the measured reflectivity distribution to a nominal distribution of the reflectivity over the surface of the multilayer system, determining at least one partial surface having a measured reflectivity above the nominal reflectivity; and irradiating the at least one partial surface with ions or electrons.

Growing community of inventors

Essingen, Germany

Joachim Kalden