Ion implantation damage annealing in 4H-SiC monitored by scanning spreading resistance microscopy

To obtain a better understanding of the damage annealing process and dopant defect incorporation and activation we have implanted epitaxially grown 4H-SiC layers with high doses of Al+ ions. Cross-sections of the samples are investigated by scanning spreading resistance microscopy (SSRM) using a commercial atomic force microscopy (AFM). The defects caused by the implanted ions compensate for the doping and decrease the charge carrier mobility. This causes the resistivity to increase in the as-implanted regions.The calculated profile of implanted ions is in good agreement with the measured ones and shows a skewed Gaussian shape. Implanted samples are annealed up to 400 °C. Despite these low annealing temperatures we observe a clear improvement of the sample conductivity in the as-implanted region.