Ion implantation and thermal annealing in silicon carbide and gallium nitride

Ion-beam-induced disordering in single crystals of 6H-SiC and single-crysta l films of gallium nitride (GaN) has been investigated using ion-channeling methods. Amorphization in GaN requires a dose that is about 30 and 100 tim es higher than in silicon carbide (SiC) at 180 and 300 K. respectively. Dyn amic defect-recovery processes in both materials increase with increasing i rradiation temperature. Amorphization in SiC is consistent with a combined direct-impact and defect-stimulated process. Three recovery stages are obse rved on both the Si and C sublattices under isochronal annealing in Au2+-ir radiated 6H-SiC. In GaN, an intermediate saturation state is observed for d isordering 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 dur ing post-implantation annealing at 870 K. (C) 2001 Elsevier Science B.V. Al l rights reserved.