ALEXANDRIA, Va., July 3 -- United States Patent no. 12,347,651, issued on July 1, was assigned to Tokyo Electron Ltd. (Tokyo).
"Etching method and plasma processing apparatus" was invented by Koki Tanaka (Miyagi, Japan), Ryu Nagai (Miyagi, Japan), Takatoshi Orui (Miyagi, Japan) and Ryutaro Suda (Miyagi, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A disclosed etching method includes (a) forming a protective film on a surface in a chamber. The etching method further includes (b) etching an etch film of a substrate by using hydrogen fluoride within the chamber. The substrate includes the etch film and a mask provided on the etch film. The protective film is formed of the same type of material as a mate...