Dry ex situ cleaning processes for (0001)_Si 6H-SiC surfaces

A completely dry ex situ cleaning process based on UV/O₃ oxidation and HF vapor exposure for removal of residual C and oxide, respectively, from (0001)_Si [the silicon-terminated surface of SiC] 6H-SiC surfaces to levels equivalent to or better than conventional wet chemical ex situ processing has been demonstrated. X-ray photoelectron spectroscopy (XPS) of surfaces exposed to UV-generated ozone revealed the formation of carbon and silicon oxides, as indicated by the broad Si-O Si 2p peak at 102.4 eV (full width at half-maximum = 2.1 eV) and a shift in the surface C 1s peak from 283.6 to 284.2 eV, respectively. Evidence for a reduction in the amount of surface C was shown by an increase in the ratio of the SiC C peak to the surface C peak from 0.8 to 2.7 after the UV/O₃ treatment. Removal of the UV/O₃ silicon oxide via exposure to the vapor from a 10:1 buffered HF solution was indicated by the absence (below the XPS detection limit) of the Si-O Si 2p peak at 102.4 eV. However, this last process results in a F-terminated surface.