Energetics of native point defects in cubic silicon carbide
INFM and Department of Physics University of Cagliari, Cittadella Universitaria, 09124 Monserrato (CA), Italy
Corresponding author: a firstname.lastname@example.org
Published online: 28 May 2004
In this work we present a detailed investigation of native point defects energetics in cubic SiC, using state-of-the-art first principles computational method. We find that, the carbon vacancy is the dominant defect in p-type SiC, regardless the growth conditions. Silicon and carbon antisites are the most common defects in n-type material in Si-rich and C-rich conditions respectively. Interstitial defects and silicon vacancy are less favorite from the energetic point of view. The silicon vacancy tends to transform into a carbon vacancy-antisite complex and the carbon interstitial atom prefers to pair to a carbon antisite. The dumbbell structure is the lowest-energy configuration for the isolated carbon interstitial defect, and the tetrahedral interstitial silicon is a stable structure in p-type and intrinsic conditions, while in n-type material the dumbbell configuration is the stable one. Our results suggest that, in samples grown in Si-rich stoichiometric conditions, native defects are a source of n-doping and of compositional unbalance of nominally intrinsic SiC, in accord with experimental evidence.
PACS: 61.72.Ji – Point defects (vacancies, interstitials, color centers, etc.) and defect clusters / 68.55.Ln – Defects and impurities: doping, implantation, distribution, concentration, etc. / 74.62.Dh – Effects of crystal defects, doping and substitution
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004