ALEXANDRIA, Va., Sept. 10 -- United States Patent no. 12,411,420, issued on Sept. 9, was assigned to KLA Corp. (Milpitas, Calif.).
"Small in-die target design for overlay measurement" was invented by Vladimir Levinski (Migdal HaEmek, Israel).
According to the abstract* released by the U.S. Patent & Trademark Office: "An overlay metrology system may generate overlay measurements based on isolated images of features on different layers of an overlay target. For example, a target may include a first-layer structure including periodic features with a fine pitch selected to be unresolved by the overlay metrology system, where the gratings structures are oriented to rotate a polarization of rotated diffraction orders relative to a polarization ...