ABINITIO INVESTIGATION OF CARBON-RELATED DEFECTS IN SILICON

Ab initio total-energy calculations based on the local-density-functio nal, pseudopotential, and super-cell approximations are performed to i nvestigate carbon defects in silicon. The geometry and the formation e nergy of substitutional and impurity-vacancy defects are studied inclu ding the relaxation of nearest and next-nearest neighbors. Results for substitutional carbon appear to be consistent with a recently suggest ed reinterpretation of the available experimental formation energy dat a. Results for the interaction energy between a carbon atom and a sili con vacancy predict a small binding energy of 0.19 eV.