Using density functional theory calculations, an examination was made of the structure and stability of extendable self-interstitial cluster configurations (In,n = 12,16) with four-atom periodicity in crystalline silicon under biaxial strain (−4% ≤ ε ≤ 4%) on Si(100). In the absence of strain, the ground state configurations of I12 and I16 share a common structure (I12-like) with C2h symmetry and a four-atom repeating unit; however, an extended configuration was identified which was based upon I4 (D2d symmetry) cluster aggregates [(I4)m(m = 3,4)] along 〈110〉 that were more favourable under certain magnitudes of strain. While both the I12-like and (I4)m configurations exhibited relative stabilities that were a function of both strain and orientation, the larger (I4)m orientation effect was the primary reason that these structures were preferred in both highly tensile and highly compressive environments. This suggested that I4 derivatives may participate in the growth transition of Si self-interstitial clusters in the compact-to-extended size regime (10 ≤ n ≤ 20) under strain.

Prediction of the Formation of Stable Periodic Self-Interstitial Cluster Chains [(I4)m, m = 1–4] in Si under Biaxial Strain. R.J.Bondi, S.Lee, G.S.Hwang: Applied Physics Letters, 2009, 94[26], 264101