A molecular dynamics study of <111> growth of silicon from melt under stress

Molecular dynamics (MD) simulations of <111> growth of silicon from melt under compressive stress have been carried out. The effect of stress on the growth mechanism and the defects formation has been studied through the simulations. Atomic interactions were described using Tersoff potential. The results indicate that the crystal growth is restrained under uniaxial compressive stress in the initial stage, but the crystal growth velocity returns to the level in absence of stress while the stress is released due to the appearance of dislocations. The competition between the FCC and the HCP stacking of biatom-layer (111) plane is discussed when silicon grows along the [111] direction from melt. In applying stress, the chance of nucleation and growth of HCP configuration increases, and consequently stacking fault area forms. The Shockley partial dislocations appear on the boundary between the normal area and the stacking fault area. Correspondingly, the stress is released, and the crystal growth velocity is restored.