Results of reactive ion etching studies, performed in SF6, on (111) oriented beta-SiC and TiC are presented. The beta-SiC etch rate increased with increasing SF6 pressure and with increasing incident RF power. The contribution of sputter etching, relative to chemical etching, decreased with increasing SF6 pressure and increased with increasing incident RF power. As-etched surf aces were free of residue under all etching conditions. The as-etched surf ace morphologies were smooth, and essentially independent of etching conditions at incident RF powers >1000 W; less than or equal to 100 W, the surface morphology became progressively rougher as the incident RF power was decreased. The electrical properties of the as-etched beta-SiC surfaces ranged from passive to very conductive, and did not correlate with etching conditions. The as-etched sidewalls of beta-SiC and TiC mesas were vertical under all conditions investigated.