Nanoscale structures formed in silicon cleavage studied with large-scale electronic structure alculations; surface reconstruction, step and bending

摘要

The 10-nm-scale structure in silicon cleavage is studied by the quantummechanical calculations for large-scale electronic structure. The cleavageprocess on the order of 10 ps shows surface reconstruction and step formation.These processes are studied by analyzing electronic freedom and compared withSTM experiments. The discussion presents the stability mechanism of theexperimentally observed mode, the $(111)$-$(2 x 1)$ mode, beyond thetraditional approach with surface energy. Moreover, in several results, thecleavage path is bent into the experimentally observed planes, owing to therelative stability among different cleavage modes. Finally, several commonaspects between cleavage and other phenomena are discussed from the viewpointsof the nonequilibrium process and the 10-nm-scale structure.