Formation mechanism of twin boundaries in silicon multicrystals during crystal growth

Formation mechanism of twin boundaries in silicon multicrystals during crystal growth was investigated by using in-situ observation of the growth interface and following characterization of microstructures of the grown crystal. The crystal growth experiments were performed under two different conditions, which are constant cooling rate and intentionally changed crystal growth rate. Under both the conditions, twin boundaries were more frequently formed when the growth rate drastically increased than when the growth rate was constant in high value. Based on these new findings, formation mechanism of twin boundaries are discussed in terms of formation energy.