Elastic interaction energy between a silicon interstitial and a carbon substitutional in a silicon crystal

The strain interaction energy between a silicon interstitial and a carbon substitutional in a silicon crystal was modeled by a continuum Green’s function method and by atomistic simulation. The interaction energy is proportional to d−3, where d is separation distance between the defects. The pair interaction energy was found to be less than 0.04 meV for d 6 nm increasing to more than about 0.1 meV for d 3 nm. The energies are unlikely to influence the diffusional behavior of the defects except at distances of one or two unit cells. The potential between the point defects is repulsive if they are oriented along the 100 crystal axis, but attractive if they are positioned along 110 or 111 .