Multi-Axial Channeling Study of Disorder in Gold Implanted 6H-SiC

Single-crystal wafers of 6H-SiC were irradiated at 300 K with 2 MeV Au2+ ions over fluences ranging from 0.029 to 0.8 ions/nm2. The accumulated disorder on both the Si and C sublattices in the irradiated specimens has been studied in situ using 0.94 MeV D+ channeling along<0001><102> and <101>axes. At low doses, results show that some of the Si and C defects are well aligned with the <0001> axis with more C defects shielded by the <0001> atomic rows; a higher level of C disorder is observed, which is consistent with a smaller threshold displacement energy on the C sublattice. There is only a moderate recovery of disorder, produced at and below 0.058 Au2+/nm2, during the thermal annealing at 570 K; similar behavior is observed in the higher-dose samples annealed between 720 and 870 K. The results suggest the presence of defect clusters and amorphous domains formed during the Au2+ irradiation. Reordering process at 570 K in the weakly damaged 6H-SiC (0.12 A u2+/nm2, 300 K) appears to occur closely along the <101> direction