ALEXANDRIA, Va., April 15 -- United States Patent no. 12,600,909, issued on April 14, was assigned to RASA INDUSTRIES LTD. (Tokyo).
"Etching solution composition" was invented by Sho Nagao (Tokyo), Tomohiro Inoue (Tokyo), Takao Mitsui (Tokyo), Nobuhiro Oshita (Tokyo) and Reiji Uchida (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "Provided is an etching solution composition that can have both a higher etch selectivity of silicon nitride and a reduction in the deposition of silica on the surface of silicon oxide. An inorganic acid-based etching solution composition for selectively etching away silicon nitride from a semiconductor containing silicon nitride and silicon oxide, the etching solution composi...