Ab initio density-functional supercell calculations of hydrogen defects incubic SiC - art. no. 245202

Based on ab initio density-functional calculations in supercells of 3C-SiC, the stable configurations of hydrogen and dihydrogen defects have been est ablished. The calculated formation energies are used to give semiquantitati ve estimates for the concentration of hydrogen in SiC after chemical vapor deposition, low temperature H-plasma anneal, or heat treatment in high temp erature hydrogen gas. Vibration frequencies, spin distributions, and occupa tion levels were also calculated in order to facilitate spectroscopic ident ification of these defects. (V+nH) complexes are suggested as the origin of Some of the signals assigned earlier to pure vacancies. Qualitative extrap olation of our results to hexagonal polytypes explains observed electrical passivation effects of hydrogen.