Oxide layers on the carbon face of 6H silicon carbide substrates
Electronic grade wafers of 6H SiC have been given a surface oxide layer on the carbon face by either conventional thermal oxidation or low-temperature plasma oxidation. Transmission electron microscopy, energy-dispersive x-ray and parallel electron energy loss, have been used to characterize the layer and its interface with the parent carbide. In both cases the oxide is close to Si2CO6 in composition but has a higher oxygen content at the surface. The plasma-grown oxide displays a higher proportion of p-bonded carbon than the SiC substrate does.