US Patent Issued to KLA on Aug. 25 for "Off-axis through the lens mutually coherent dark field imaging system with incoherent light for overlay metrology" (California Inventors)

ALEXANDRIA, Va., Aug. 25 -- United States Patent no. 12,717,248, issued on Aug. 25, was assigned to KLA Corp. (Milpitas, Calif.).

"Off-axis through the lens mutually coherent dark field imaging system with incoherent light for overlay metrology" was invented by Wenjian Cai (Sunnyvale, Calif.), Andrew V. Hill (Berkley, Calif.), Xuefeng Liu (San Jose, Calif.), John Fielden (Los Altos, Calif.), Yung-Ho Alex Chuang (Cupertino, Calif.) and Huimin Ouyang (Mountain View, Calif.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A metrology system is disclosed. The system includes an incoherent illumination source to generate incoherent illumination. The system includes a diffraction grating to split the incoherent illu...