Pit formation and surface morphological evolution in Si(001) homo-epitaxy were investigated by using scanning tunnelling microscopy. Antiphase boundary was found to give rise to initial generation of pits bound by bunched DB steps. The terraces break up and were reduced to a critical nucleus size with pit formation. Due to anisotropic kinetics, a downhill bias diffusion current, which was larger along the dimer rows through the centre area of the terrace than through the area close to the edge, led to the prevalence of pits bound by {101} facets. Subsequent annealing results in a shape transition from {101}-faceted pits to multi-faceted pits.

STM Observation of Pit Formation and Evolution during the Epitaxial Growth of Si on Si(001) Surface. M.J.Xu, J.Mayandi, X.S.Wang, J.F.Jia, Q.K.Xue, X.M.Dou: Chinese Physics B, 2010, 19[10], 106102