Theoretical Investigations of Complexes of p-Type Dopants and Carbon Interstitial in SiC: Bistable, Negative-U Defects

Interaction of boron and aluminum with interstitial carbon is studied using first principles calculations. It is shown that carbon can form very stable complexes with Al and B, forming a family of negative-U bistable defects with deep levels. The influence of this effect on the activation rate of p-type implants is discussed.