ALEXANDRIA, Va., Feb. 19 -- United States Patent no. 12,227,673, issued on Feb. 18, was assigned to CMC MATERIALS LLC (Aurora, Ill.).
"Composition and method for silicon nitride CMP" was invented by Fernando Hung Low (Aurora, Ill.), Steven Kraft (Plainfield, Ill.) and Roman A. Ivanov (Aurora, Ill.).
According to the abstract* released by the U.S. Patent & Trademark Office: "The invention provides a chemical-mechanical polishing composition for polishing a silicon nitride containing substrate. The composition includes an aqueous carrier; cationic silica particles dispersed in the aqueous carrier, the cationic silica abrasive particles having a zeta potential of at least 10 mV in the polishing composition; a polishing additive selected from...