Twin formation in silicon growth from the melt was examined by molecular dynamics simulations. For a moderate undercooling of 25K, it was found that twins did not nucleate on (111) microfacets in the perfect crystal, but exclusively occurred in the vicinity of grain boundaries. Only at an undercooling of 150K was the formation of metastable twin bounded loops with incoherent interfaces to the matrix, consisting of coherency and anticoherency dislocations, observed. The nucleation of stable twins in silicon growth required the presence of a grain boundary or more general of a three-phase boundary, but was unlikely to occur on ideal (111) facets because of the excess energy of the interfacial area between matrix and twinned crystal.

Formation of Parallel (111) Twin Boundaries in Silicon Growth from the Melt Explained by Molecular Dynamics Simulations. J.Pohl, M.Müller, A.Seidl, K.Albe: Journal of Crystal Growth, 2010, 312[8], 1411-5