It was noted that defect energetics in SiC were widely studied by using Tersoff potentials. However, these potentials did not provide a good description of interstitial properties. An empirical many-body interatomic potential was developed here by fitting various equilibrium properties and stable defect configurations in bulk SiC, using a lattice relaxation fitting approach. This parameterized potential was used to calculate defect formation energies and to determine the most stable configurations for interstitials by using the molecular dynamics method. Although the formation energies of vacancies were smaller than those obtained by using ab initio calculations, the properties of antisite defects and interstitials were in good agreement with the results calculated by using ab initio methods. It was found that the most favorable configurations for C interstitials were <100> and <110> dumb-bells on both Si and C sites; with formation energies ranging from 3.04 to 3.95eV. The most favorable Si interstitial was the tetrahedral interstitial site, surrounded by four C atoms; with a formation energy of 3.97eV.

Empirical Potential Approach for Defect Properties in 3C-SiC. F.Gao, W.J.Weber: Nuclear Instruments and Methods in Physics Research Section B, 2002, 191[1-4], 504-8