The diffusion of transition metals in 4H-SiC was investigated by secondary ion mass spectrometry using epilayers and substrates implanted with titanium (Ti), chromium, iron or nickel. Implanted Cr, Fe, and Ni atoms diffuse by subsequent Ar annealing at 1780C in n-type 4H-SiC epilayers. In n+-type substrates, the diffusivities of Ti, Cr, and Fe were almost negligible, while only Ni diffuses. By the helium implantation following the implantation of transition metals, no diffusion of Ti, Cr and Fe was observed in epilayers. The diffusion of transition metals in SiC was discussed based on the results of first-principles calculation.

Diffusion of Transition Metals in 4H-SiC and Trials of Impurity Gettering. K.Danno, H.Saitoh, A.Seki, T.Shirai, H.Suzuki, T.Bessho, Y.Kawai, T.Kimoto: Applied Physics Express, 2012, 5[3], 031301