A simple model explaining the preferential (100) orientation of silicon thin films made by aluminum-induced layer exchange

In the aluminum-induced layer exchange process polycrystalline silicon thin films can be formed on foreign substrates at low temperatures. These films exhibit a preferential (1 0 0) crystal orientation, that depends on the annealing temperature. Further, the preferential orientation is sensitive to the nature of the Al oxide layer between the Si and the Al. A model based on preferential nucleation is presented which elucidates a possible origin of the preferential (1 0 0) orientation and its sensitivity to temperature and the aluminum oxide interlayer.