Damage formation in SiC ion implanted at 625 K

Damage formation in 4H-SiC during ion implantation at 625 K is studied applying Rutherford backscattering spectrometry (RBS) in channeling configuration. For comparison two selected samples are analysed by cross section transmission electron microscopy (TEM). The results for dual implantation of the self-ions Si and C with the ratio 1:1 are compared with those obtained for Ag ion implantation. It is found that the evolution of damage as a function of the number of displacements per lattice atom proceeds in two steps and is almost independent of the ion species implanted. The second significant increase of the damage concentration starts obviously when the relative volume increase introduced by the implanted ions exceeds a critical value of about 6.10-3. The damage produced at high ion fluences consists of point defect clusters and, probably, extended defects.