Using first-principles density-functional theory calculations, variations in the structure and stability of small self-interstitial clusters (In, n ≤ 10) in crystalline silicon were examined over a range of biaxial strain conditions (−3% ≤ ε ≤ 3%) on Si(100). Under the strain conditions considered, there was no significant deviation in the ground-state configuration of any cluster from the strain-free case. However, the relative stability of I4 and I8 was significantly increased under both compressive and tensile strain conditions, while other cluster sizes generally showed less sensitivity to changes in strain. This suggested that I4 and I8 likely played an even larger role in the clustering/dissolution of interstitial defects in strained Si relative to strain-free Si. It was found that the noteworthy strain dependence of I4 and I8 was attributed to the unique shape and symmetry of the I4-like core which allowed reorientation within the lattice that was dependent on the compressive/tensile nature of biaxial strain

Biaxial Strain Effects on the Structure and Stability of Self-Interstitial Clusters in Silicon. R.J.Bondi, S.Lee, G.S.Hwang: Physical Review B, 2009, 79[10], 104106