Characterisation of defects in p-type 4H-, 6H- and 3C-SiC epilayers grown on SiC substrates

Abstract

The defects in p-type 4H-, 6H- and 3C-SiC epilayers grown on SiC substrates were characterised. The surface roughness after etching and the full width at half maximum of the X-ray rocking curves of the epilayers revealed more dislocations in those grown on the on-axis substrates than on the off-axis ones; the deep levels were also significant for the epilayers grown on the on-axis substrates. These results suggested that the dislocations, double-positioning boundaries and stacking faults in the SiC epilayers grown on on-axis substrates induced deep levels in the bandgap. Step-flow epitaxy on off-angle substrates is the best method for p-type SiC epilayers fabrication, and thus we need novel growth technique to obtain high quality 3C-SiC epilayers.