Formation mechanism of twin boundaries during crystal growth of silicon

The formation mechanism of twin boundaries in multicrystalline Si was studied using an in situ observation technique. We directly observed the growing interface and analyzed change in the growth rate. We found that the formation of twin boundaries in crystal grains was always accompanied by a marked increase in the growth rate and they were rarely formed when the growth rate was constant at a high value. The formation mechanism is discussed from the viewpoint of driving force.