US Patent Issued to Tokyo Electron on Sept. 23 for "Method to selectively etch silicon nitride to silicon oxide using water crystallization" (New York, California Inventors)

ALEXANDRIA, Va., Sept. 23 -- United States Patent no. 12,424,447, issued on Sept. 23, was assigned to Tokyo Electron Ltd. (Tokyo).

"Method to selectively etch silicon nitride to silicon oxide using water crystallization" was invented by Yu-Hao Tsai (Albany, N.Y.), Mingmei Wang (Fremont, Calif.) and Du Zhang (Albany, N.Y.).

According to the abstract* released by the U.S. Patent & Trademark Office: "Embodiments of improved processes and methods that provide selective etching of silicon nitride are disclosed herein. More specifically, a cyclic, two-step dry etch process is provided to selectively etch silicon nitride layers formed on a substrate, while protecting oxide layers formed on the same substrate. The cyclic, two-step dry etch proces...