Calculations predicted that the C antisite was the most abundant intrinsic defect in SiC for a wide range of dopings. However, the isolated C antisite was optically and electronically inactive and therefore difficult to observe. However, CSi could trap mobile impurities, to form electrically active complexes. It was shown, by ab initio super-cell calculations, that the H interstitial was trapped by the C antisite to form an electrically active defect which might be detectable by different spectroscopic techniques. The key to activating CSi by H was to introduce sufficient amount of H in the SiC samples and to avoid formation of vacancies or B-H complexes. It was found that the concentration of CSi + H complex was above 1013/cm3 in highly doped p-type chemical vapor deposited layers as well as in highly doped p-type and n-type SiC samples annealed in high-temperature high-pressure H2 gas. The concentration of CSi + H complex could be enhanced in Al-doped CVD and high-temperature high-pressure SiC samples by applying the appropriate post-annealing temperature. The CSi + H complex might be also detected in Al-doped SiC samples irradiated at room temperature by low energy H2+ ions.

Possibility of the Electrical Activation of the Carbon Antisite by Hydrogen in SiC. A.Gali, P.Deák, N.T.Son, E.Janzén: Physical Review B, 2005, 71[3], 035213 (6pp)