Surface roughness in Al-implanted 4H-SiC substrates for different Al concentrations and after 1950°C post implantation annealing

The surface morphology of a 4HSiC sample implanted by an Al concentration of 1.6×10^20 cm-3 before and after the post implantation annealing is presented. The RMS roughness of the virgin and annealed samples are 0.39±0.04 and 0.56±0.08 nm, respectively. The AFM image of the annealed sample shows the formation on the surface of few nanometer deep circular pits with a diameter of ? 1 ?m (Figure 1b). A similar morphology is observed in the annealed samples implanted by the other Al concentration values of this study. No significant dependence of the surface roughness on the implanted Al ion dose was observed.