The introduction of defects into n-type 6H- and 4H- material, due to room-temperature proton implantation, was studied by using the electron paramagnetic resonance technique. In order to study defect introduction into a particular region, 12MeV implantation into 300μm-thick samples was used so that the protons completely crossed the sample. Three dominant paramagnetic defects were observed in both types of material and were attributed to a Si monovacancy in the negative charge state, and to a neutral Si monovacancy in hexagonal or quasi-cubic lattice sites. The concentrations of all 3 defects increased linearly with proton dose. The total introduction rate was of the order of 19/cm. No C-vacancy related defect was observed. Annealing at 1100C was sufficient to anneal out the VSi defects, and restore n-type conductivity. It was noted that the observation of a neutral Si vacancy at hexagonal and quasi-cubic sites, under thermal equilibrium conditions at 4K, did not support their previous attribution to an excited state.

Proton Implantation-Induced Defects in n-Type 6H- and 4H-SiC: an Electron Paramagnetic Resonance Study. H.J.von Bardeleben, J.L.Cantin, I.Vickridge, G.Battistig: Physical Review B, 2000, 62[15], 10126-34