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

A completely dry ex situ cleaning process based on UV/O-3 oxidation and HF vapor exposure for removal of residual C and oxide, respectively, from (000 1)(Si) [the silicon-terminated surface of SiC] 6H-SiC surfaces to levels eq uivalent to or better than conventional wet chemical ex situ processing has been demonstrated. X-ray photoelectron spectroscopy (XPS) of surfaces expo sed to UV-generated ozone revealed the formation of carbon and silicon oxid es, as indicated by the broad Si-O Si 2p peak at 102.4 eV (full width at ha lf-maximum = 2.1 eV) and a shift in the surface C Is peak from 283.6 to 284 .2 eV, respectively. Evidence for a reduction in the amount of surface C wa s 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/O-3 treatment. Removal of the UV/O-3 silicon oxide via exposure to the vapor from a 10:1 buffered HF solution was indica ted by the absence (below the XPS detection limit) of the Si-O Si 2p peak a t 102.4 eV. However, this last process results in a F-terminated surface.