Method of etching a wafer having high anisotropy with a plasma gas containing halogens and in inert element

摘要

Fine processing is performed by using gas which contains halogen in such a manner that halogen ions contributing to an etching process and ions of a light element, the mass of which is smaller than that of the halogen ion and which does not react with a semiconductor wafer, are present in a plasma generated due to electron cyclotron resonance. Since energy in the plasma is in inverse proportion to the mass, the disorder motion of the halogen ions having large mass can be restrained. Therefore, the halogen ions can be made perpendicularly incident upon the surface of the semiconductor wafer. Consequently, etching process revealing high anisotropy can be performed.