Comparison of electronic stopping cross sections for channeled implantation of Al ions between the ⟨0001⟩ and ⟨11 2 3⟩ directions in 4H-SiC

Electronic stopping cross sections (S e) for channeled implantation of Al ions in 4H-SiC were compared between the 0001 and 11 2 over bar 3 directions. We first modeled S- e for random implantation (S (e) (random)) by combining the Firsov equation at an Al-ion energy E < 8.6 MeV with the constant (i.e. 4.22 x 10-13 eV cm2/atom) at E > 8.6 MeV. We then assumed S (e) for channeled implantation being k S- e (random) and fitted k to the reported maximum channeled ranges of 18-20 MeV Al in 4H-SiC. The resultant k 1123 of 0.53 being smaller than k( (0001))of 0.70 was consistent with the difference in the maximum impact parameters.