Dislocation behavior in seed-cast grown Si ingots based on crystallographic orientation

This study concentrates on dislocation behavior during Si growth by the seed-cast method in different crystallographic orientations. Two methods were combined: (1) Si crystal growth in different seed orientations and (2) float zone Si-annealing experiment to obtain the purely thermal stress-induced dislocation density. The main focus is on the difference between the (111) and the (100) growth directions. It is found that peripheral areas are dominated by thermal stress-induced dislocation densities. Central ingot areas are dominated by other dislocation sources. By comparing the (100) and the (111) orientations, it was found that a difference in dislocation motion exists. This difference is caused by a different activation of slip systems, causing long slip lines in the (111) orientation. It is shown that numerical simulation has problems describing this long-range dislocation slip.