Dopant diffusion and surface morphology of vanadium implanted 4H-silicon carbide

The diffusion behaviours of vanadium implanted p- and n-type 4H-SiC are investigated by using the secondary ion mass spectrometry (SIMS). Significant redistribution, especially out-diffusion of vanadium towards the sample surface is not observed after 1650℃ annealing for both p- and n-type samples. Atomic force microscopy (AFM) is applied to the characterization of surface morphology, indicating the formation of continuous long furrows running in one direction across the wafer surface after 1650℃ annealing. The surface roughness results from the evaporation and re-deposition of Si species on the surface during annealing. The chemical compositions of sample surface are investigated using x-ray photoelectron spectroscopy (XPS). The results of C 1s and Si 2p core-level spectra are presented in detail to demonstrate the evaporation of Si from the wafer and the deposition of SiO₂ on the sample surface during annealing.