A molecular dynamics study of nucleation of dislocation in growth of silicon from melt

Molecular dynamics (MD) simulations of growths of crystalline silicon from the melt along < 100 >, < 110 > and < 112 > directions have been carried out. Tersoff potential is employed for computing atomic interaction. The results show that in the growths along < 100 >, < 110 >, no dislocation was formed, while in the growth along < 112 >, more than one dislocations formed. The dislocation formed is identified as a partial dislocation lying on an on {111} plane, with segments of 30 degrees partial dislocation, 90 degrees partial dislocations and some kinks. The dislocation nucleates stochastically at the crystal/melt interface, where atoms interact with each other to form at least two units of stable periodic non-six-member-ring groups. Once formed, it extends with the crystal growth, with its two ends attached to the crystal/melt interface. The < 112 > growth distinguished from the < 100 > and < 110 > growths by its prone-to-{111}-faceting and twinning, which may be the cause of the significantly higher probability of dislocation nucleation in the < 112 > growth. (C) 2016 Elsevier B.V. All rights reserved.