Plasma-processing method and an apparatus for carrying out the same

摘要

A plasma-etching apparatus is capable of etching a film of a workpiece with a plasma produced in an evacuated etching chamber at a high etch selectivity relative to an underlying film or a resist film. The frequency of a RF bias voltage applied to a sample table by a RF power source is adjusted so that the ion energy of the plasma is distributed in a saddle-peak energy distribution pattern. The film is etched at a high etch selectivity relative to a material having a threshold ion energy.