Etching method and apparatus

摘要

An etching method, for selectively etching a silicon nitride film to a silicon oxide film by using a processing gas in a processing chamber including an electrode therein, includes the steps of mounting a target object having the silicon oxide film and the silicon nitride film onto the electrode and etching the silicon nitride film by introducing a gaseous mixture containing CF₄ gas, H₂ gas and N₂ gas as a processing gas into the processing chamber and applying a high frequency power of 0.20 W/cm² or less to the electrode while maintaining a pressure in the processing chamber to be equal to or smaller than 4 Pa.