SULFUR-HEXAFLUORIDE REACTIVE ION ETCHING OF (111) BETA-SIC EPITAXIAL LAYERS, GROWN ON (111) TIC SUBSTRATES

Results of reactive ion etching studies, performed in SF6, on (111) or iented beta-SiC and TiC are presented. The beta-SiC etch rate increase d with increasing SF6 pressure and with increasing incident RF power. The contribution of sputter etching, relative to chemical etching, dec reased with increasing SF6 pressure and increased with increasing inci dent RF power. As-etched surf aces were free of residue under all etch ing conditions. The as-etched surf ace morphologies were smooth, and e ssentially independent of etching conditions at incident RF powers >10 00 W; less than or equal to 100 W, the surface morphology became progr essively rougher as the incident RF power was decreased. The electrica l properties of the as-etched beta-SiC surfaces ranged from passive to very conductive, and did not correlate with etching conditions. The a s-etched sidewalls of beta-SiC and TiC mesas were vertical under all c onditions investigated.