The results generated by large-scale molecular-dynamics simulations of self-interstitial clusters in crystalline silicon were analyzed by using a recently developed computational method for probing the thermodynamics of defects in solids. In this approach, the potential-energy landscape was sampled with lengthy molecular-dynamics simulations and repeated energy minimizations in order to build distribution functions that quantitatively described the formation thermodynamics of a particular defect cluster. Using this method, a comprehensive picture for interstitial aggregation was proposed. In particular, it was found that both vibrational and configuration entropic factors played important roles in determining self-interstitial cluster morphology. In addition to the expected role of temperature, it was also found that applied (hydrostatic) pressure and the . commensurate lattice strain greatly influence the resulting aggregation pathways. Interestingly, the effect of pressure appeared to manifest not by altering the thermodynamics of individual defect configurations but rather by changing the overall energy landscape associated with the defect. These effects appeared to be general and were predicted using multiple, well-tested, empirical interatomic potentials for silicon. The results suggested that internal stress environments within a silicon wafer (e.g., created by ion implantation) could have profound effects on the observed self-interstitial cluster morphology.

Detailed Microscopic Analysis of Self-Interstitial Aggregation in Silicon. II. Thermodynamic Analysis of Single Clusters. S.S.Kapur, A.M.Nieves, T.Sinno: Physical Review B, 2010, 82[4], 045206