Patent attributes
A method of atomic layer etching a silicon oxide film or a silicon nitride film is provided. Atomic layer etching (ALE) is performed by repeating three steps of (1) hydrogenation step of hydrogenating a surface by irradiating a silicon oxide film or a silicon nitride film with a plasma containing H, (2) acid halide adsorption step of causing chemisorption of an acid halide represented by a formula of Rf—COX (Rf is H, F, a substituent consisting of C and F or consisting of C, H, and F, or —COX; each X is independently any halogen atom of F, Cl, Br and I) on the surface by reacting the acid halide with the hydrogenated surface through exposure to the acid halide, and (3) etching step of etching a single atomic layer by inducing chemical reactions on the surface of the acid halide-adsorbed silicon oxide film or silicon nitride film through irradiation with a plasma containing a noble gas (at least any one of He, Ar, Ne, Kr, and Xe).
