ALEXANDRIA, Va., March 26 -- United States Patent no. 12,257,666, issued on March 25, was assigned to EBARA Corp. (Tokyo).
"Surface height measurement method using dummy disk" was invented by Hiroyuki Shinozaki (Tokyo) and Yasuyuki Motoshima (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method is provided and includes making a polishing table and a dummy disk rotate; bringing the dummy disk into contact with a table surface of the polishing table while a liquid is supplied to the table surface; measuring heights of the table surface at a plurality of measurement points while the dummy disk is moved on the table surface; and creating a table profile showing tilt of the table surface from measurement...