ALEXANDRIA, Va., Nov. 11 -- United States Patent no. 12,468,228, issued on Nov. 11, was assigned to Carl Zeiss SMT GmbH (Oberkochen, Germany).
"Illumination optical system for EUV projection lithography" was invented by Joachim Kalden (Essingen, Germany) and Stig Bieling (Aalen, Germany).
According to the abstract* released by the U.S. Patent & Trademark Office: "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 b...