Dry etching of CdTe/GaAs epilayers using CH4/H2 gas mixtures

A CH4/H2 gas mixture has been used for the dry etching of (100) and (111) oriented CdTe epilayers in a barrel reactor. The effects of various process parameters on etch rate and surface morphology were studied with special attention paid to the gas composition and the total chamber pressure as well as the crystallographic orientation of the sample. Clear evidence is found for both isotropic and preferential etching along crystallographic planes depending on the set of etch parameters used.