Ion implantation and thermal annealing in silicon carbide and gallium nitride

Ion-beam-induced disordering in single crystals of 6H-SiC and single-crystal films of gallium nitride (GaN) has been investigated using ion-channeling methods. Amorphization in GaN requires a dose that is about 30 and 100 times higher than in silicon carbide (SiC) at 180 and 300 K, respectively. Dynamic defect-recovery processes in both materials increase with increasing irradiation temperature. Amorphization in SiC is consistent with a combined direct-impact and defect-stimulated process. Three recovery stages are observed on both the Si and C sublattices under isochronal annealing in Au2+-irradiated 6H-SiC. In GaN, an intermediate saturation state is observed for disordering at the damage peak, which suggests enhanced defect annihilation processes. Implanted Au diffuses towards the surface during implantation at 300 K and undergoes further diffusion into the amorphous surface layer during post-implantation annealing at 870 K