ETCHING METHOD AND DEVICE

摘要

An etching method and apparatus for etching a silicon oxide film selectively with respect to a silicon nitride film formed on a substrate are provided. A processing gas containing a plasma excitation gas and a CHF-based gas is introduced into a processing chamber such that a flow rate ratio of the CHF-based gas to the plasma excitation gas is 1/15 or higher. By generating a plasma in the processing chamber, the silicon oxide film is etched selectively with respect to the silicon nitride film formed on the substrate in the processing chamber.