The effect of grain boundary characteristics on the morphology of the crystal/melt interface of multicrystalline silicon

The effect of grain boundary characteristics on the crystal/melt interface morphology during the unidirectional solidification of multicrystalline Si was studied by in situ observations. It was shown that sharp and smooth grooves were formed at the crystal/melt interfaces at Σ27 and random grain boundaries, whereas no grooves were formed at Σ3 {1 1 1} twin boundaries. We explain the reasons why the grooves form at grain boundaries and discuss the impurity segregation at the grain boundary grooves on the crystal/melt interface.