The diffusion behavior of B and N implanted into 6H and 4H silicon carbide samples was investigated by using secondary ion mass spectroscopy. The samples were either co-implanted with B and N ions or implanted with each element alone. The annealing (1700C, 10 to 1800s) was performed in an Ar ambient or in Si and C vapor. Transmission electron microscopy was used to determine the structural properties of implanted layers after the annealing. The N concentration profiles remained unchanged after the annealing. B atoms exhibited transient enhanced out- and in-diffusion. The co-implantation reduced the fraction of mobile B atoms participating in out- and in-diffusion processes and resulted in an increase in the density and decrease in size of dislocation loops formed in the implanted layer. The B diffusion coefficients in both SiC polytypes were determined and a diffusion mechanism was proposed.

Diffusion of Boron in 6H and 4H SiC Co-Implanted with Boron and Nitrogen Ions. I.O.Usov, A.A.Suvorova, Y.A.Kudriavtsev, A.V.Suvorov: Journal of Applied Physics, 2004, 96[9], 4960-4