Characterization of the CH_4/H_2/Ar High Density Plasma Etching Process for HgCdTe

摘要

High density plasma etching of mercury cadmium telluride using CH_4/H_2/Ar plasma chemistries is investigated. Mass spectrometry is used to identify and monitor etch products evolving from the surface during plasma etching. The identifiable primary etch products are elemental Hg, TeH_2, and Cd(CH_3)_2. Their relative concentrations are monitored as ion and neutral fluxes (both in intensity and composition), ion energy and substrate temperature are varied. General insights are made into surface chemistry mechanisms of the etch process. These insights are evaluated by examining etch anisotropy and damage to the remaining semiconductor material. CH_4/H_2/Ar Regions of process parameter space best suited to moderate rate, anisotropic, low damage etching of HgCdTe are identified.