Fractal and Spherulitic Morphology of Silicon Nitride Crystallized from Amorphous Films

摘要

Thin films of substoiciometric silicon nitride were grown by the use of ion beam assisted deposition. The amorphous films were annealed at high temperatures (1017-1200C) to produce crystalline alpha-Si3N4. Both highly symmetric spherulitic crystal morphologies and irregular fractal aggregates were seen. In the latter case, a fractal dimension of 1.2 was measured. These two macroscopically different forms possessed correspondingly different microstructures. The morphologies were found to be determined by the temperature of the anneal. (AW)