Effect of ion current density on damage in Al ion implanted SiC

The damage created by implantation of Al ions into single crystalline 4H-SiC has been analyzed using a combination of ion beam techniques and spectroscopic ellipsometry. The samples were implanted at room temperature with 150 keV Al+ ions in the fluence range of 4 x 1014 cm-2 to 2 x 1015 cm-2 with current densities of 0.4 and 2.5 μA cm-2. In order to study simultaneously the depth distribution of the disorder produced in both the carbon and silicon sublattice, we used 3.5 MeV He beam in channeling geometry. In this condition the cross-section for carbon is enhanced by a factor of ∼6. The structural recovery of the samples after a further high temperature annealing has been studied. These results have been compared with the optical properties of the samples measured by spectroscopic ellipsometry