Lattice sites of ion-implanted Mn, Fe and Ni in 6H-SiC

Using radioactive isotopes produced at the CERN-ISOLDE facility, the lattice location of the implanted transition metal (TM) ions $^56$Mn, $^59$Fe and $^65$Ni in n-type single-crystalline hexagonal 6H-SiC was studied by means of the emission channeling technique. TM probes on carbon coordinated tetrahedral interstitial sites ($T_C$) and on substitutional silicon sites ($S_{Si,h+k}$) were identified. We tested for but found no indication that the TM distribution on $S_Si$ sites deviates from the statistical mixture of 1/3 hexagonal and 2/3 cubic sites present in the 6H crystal. The TM atoms partially disappear from $T_C$ positions during annealing at temperatures between 500 °C and 700 °C which is accompanied by an increase on $S_Si$ and random sites. From the temperature associated with these site changes, interstitial migration energies of 1.7–2.7 eV for Mn and Ni, and 2.3–3.2 eV for Fe were estimated. TM lattice locations are compared to previous results obtained in 3C-SiC using the same technique.