ALEXANDRIA, Va., Jan. 28 -- United States Patent no. 12,534,640, issued on Jan. 27, was assigned to Resonac Corp. (Tokyo).
"Polishing liquid and polishing method" was invented by Hiroshi Ono (Tokyo), Keisuke Inoue (Tokyo) and Takahiro Jinushi (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A polishing liquid for polishing a surface to be polished containing a tungsten material, the polishing liquid containing abrasive grains, an iron-containing compound, and an oxidizing agent, in which the abrasive grains include silica particles, an average particle diameter of the abrasive grains is 40 to 140 nm, and a silanol group density of the silica particles is 8.0 groups/nm2 or less. A polishing method of pol...