ALEXANDRIA, Va., Aug. 12 -- United States Patent no. 12,387,940, issued on Aug. 12, was assigned to CENTRAL GLASS COMPANY Ltd. (Ube, Japan).
"Dry etching method" was invented by Shoi Suzuki (Ube, Japan) and Akifumi Yao (Ube, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A dry etching method according to the present invention includes etching silicon nitride by bringing a mixed gas containing hydrogen fluoride and a fluorine-containing carboxylic acid into contact with the silicon nitride in a plasma-less process at a temperature lower than 100deg C. Preferably, the amount of the fluorine-containing carboxylic acid contained is 0.01 vol % or more based on the total amount of the hydrogen fluoride and t...