Nitrogen implantation in 4H and 6H–SiC

We have undertaken a physico-chemical and electrical characterisation of nitrogen ion implantations in SiC epitaxies using a large variety of experimental conditions. The samples were implanted either at room temperature (RT) or at 650°C (HT). SIMS measurements were done to compare the depth-distributions with results from TRIM92 simulations. Transmission electron microscope (TEM) analysis of these samples was carried out on cross-sectional samples using Weak Beam Dark Field imaging conditions. Van der Pauw test patterns were realised to extract the thermal dependencies of resistivity and mobility. A comparison with the conductivity and mobility obtained on films doped during epitaxy and implanted films is done. It is shown that, in the lower dose range, the ionisation and activation does not depend on the implantation temperature.