First-principles density-functional theory calculations were used to evaluate the orientation-dependent stability of small, neutral self-interstitial clusters (In, n≤4) in crystalline Si for a range of uniform strain conditions (−4 ≤ ε ≤ 4%) in both uniaxial and biaxial strain fields on Si(100). Comprehending the behaviour of these small clusters under strain was important in extending the understanding of the evolutionary cycle of interstitial defects during the ion implantation and annealing processes that occurred during semiconductor manufacturing. The calculation results suggested that strain of sufficient magnitude could contribute to significant ground-state structural distortion and even generation of different cluster configurations. The study also indicated that the relative stability change per unit change in applied strain was greater in the biaxial case than the uniaxial case for interstitial clusters. Localized strain-distribution profiles were provided, and modifications of bulk Si density of states to characterize the extent to which interstitial clusters modulate crystalline Si structure

Theoretical Characterization of Silicon Self-Interstitial Clusters in Uniform Strain Fields. R.J.Bondi, S.Lee, G.S.Hwang: Physical Review B, 2009, 80[12], 125202