ETCHING METHOD AND DEVICE

摘要

Provided are an etching method and device with which the selective etching ratio of a silicon oxide film to a silicon nitride film can be increased. A treatment gas containing a plasma excitation gas and a CHF gas is introduced to a treatment container (10) such that the flow rate ratio of the CHF gas to the plasma excitation gas is 1/15 or higher. By generating plasma inside the treatment container (10), a silicon oxide film (5) formed on a substrate (W) inside the treatment container (10) is etched selectively with respect to a silicon nitride film (1).