PLASMA ETCHING METHOD

摘要

Etching gas is introduced into a treatment chamber (16) and a plasma is generated to etch a silicon nitride film (12) which is formed on the field silicon oxide film (4) of a wafer (W). Mixed gas which contains at least CH2F2 gas and O2 gas is used as the etching gas. The treatment pressure and the mixing ratio (CH2F2/O2) are used as parameters for setting a plasma etching apparatus in accordance with the set value of the uniformity in an etched surface. The more strict the set value of the uniformity in the etched surfaces, the higher one of the treatment pressure and the mixing ratios.