Plasma etching method and apparatus, control program for performing the etching method, and storage medium storing the control program

摘要

A plasma etching method for etching an etching target layer of a silicon layer through a mask of a silicon oxide film includes the following sequential steps of forming an opening in the silicon oxide film, wherein an opening dimension of a portion between a top and a bottom surface of the mask is enlarged compared to opening dimensions of the top and the bottom surface of the mask and etching the silicon layer by using a halogen containing gas. A gaseous mixture containing HBr gas, NF₃ gas and O₂ gas is used as the halogen containing gas. A hole or a trench having an opening diameter or an opening width equal to or smaller than 0.2 mum is formed in the etching target layer. Further, a hole or a trench having an aspect ratio equal to or greater than forty is formed in the etching target layer.