Ab initio modeling and experimental study of C–B interactions in Si

Abstract

We present results of ab initio calculations for the structure and energetics of small boron-carbon-interstitial and carbon-interstitial clusters in silicon and a respective continuum model for the nucleation, growth, and dissolution of these clusters. To test our calculations, we also measure secondary-ion mass spectra of boron and carbon in a SiGeCB system, which our model reproduces well. For the considered concentration regime, we find rapid carbon diffusion, nearly immobile boron, and undersaturation of silicon self-interstitials, resulting mainly from two clusters suggested by our ab initio results, the dicarbon-interstitial cluster and the boron-carbon-interstitial cluster.