Chemical contribution of oxygen to silicon carbide plasma etching kineticsin a distributed electron cyclotron resonance (DECR) reactor

This paper deals with the influence of the oxygen additive on the fluorinat ed plasma etch rate of silicon carbide. The assumption according to which t he oxygen has a direct contribution to silicon carbide etching, by chemical reaction with carbon atoms, is generally reported in the literature. Our e tching experiments are performed in a distributed electron cyclotron resona nce reactor, on both 3C- and 6H-SiC. An SF6/O-2 gas mixture (avoiding the p resence of C species in the plasma), fluorine saturation conditions and con stant ion bombardment energy and flux are used, allowing the study of O-2 c ontribution exclusively. In these conditions, our results demonstrate the n eutrality of O-2 on SiC etching mechanisms. These results will be discussed reinforced both by several other experimental observations.