Patterning of SiC surfaces with oblique AR ion irradiation

We report on the formation of ripple patterns over silicon carbide thin films as grown on silicon substrates Si(111) and sputtered with 80 keV Ar⁺ beam to various fluences. AFM studies reveal that the ordering and homogeneity of these ripple patterns increase with ion fluence but the ripple wavelength and amplitude both increases with increasing argon ion fluence. Formation of such surface structures is attributed to the interplay between preferential sputtering and surface diffusion processes. The overall topographic evolution is discussed in light of existing theoretical models of ion beam nano-patterning. Our results reveal that ion irradiation can be exploited to fabricate controlled surface nanostructures by optimizing the irradiation parameters. (author)