US Patent Issued to Onto Innovation on Aug. 12 for "Multi-layer calibration for empirical overlay measurement" (Oregon, California, Texas Inventors)

ALEXANDRIA, Va., Aug. 12 -- United States Patent no. 12,386,271, issued on Aug. 12, was assigned to Onto Innovation Inc. (Wilmington, Mass.).

"Multi-layer calibration for empirical overlay measurement" was invented by Nigel P. Smith (Beaverton, Ore.), Francis Scott Hoover (Houston), Nicholas James Keller (La Jolla, Calif.) and Kevin Eduard Heidrich (Beaverton, Ore.).

According to the abstract* released by the U.S. Patent & Trademark Office: "Overlay is determined for a device using signals measured from the device and a signal response to overlay determined from a plurality of calibration targets. Each calibration target has the same design as the device, but includes a known overlay shift. The calibration targets may be located in a scri...