Plasma processing method and plasma processing device

Abstract

Provided is a plasma processing method and device capable of controlling the etching mask shape during a single-step process that etches a target material disposed below the etching mask. The plasma processing method includes performing selective deposition on the etching mask in separate phases, which are controlled via a periodic bias voltage signal. By tuning the bias voltage power, duration and timing, the mask height and width can be controlled and stabilized while etching on the substrate proceeds. Thus, the present method provides an etching process that allows fine control of the etching mask shape for small pattern sizes and provides high etching selectivity through deposition.