New Insight in Scandium-Mediated Growth Techniques: Sc-Related Defects in 4H-SiC and 6H-SiC

Scandium can be used to influence the stoichiometry of SiC during growth of the hexagonal polytypes. Using PL-EPR and total energy calculations in the framework of density functional theory, scandium is predicted to be built in predominantly at the Si-sublattice in form of ScSi acceptors with acceptor levels at 0.55 eV (6H-SiC) and 0.48 eV (4H-SiC). In addition, new PL-EPR spectra are found with a large anisotropy in the g-tensor suggesting defect pairs as an origin.