Element specific surface reconstructions of islands during surfactant-mediated growth on Si(111)

Abstract

The early stages of surfactant- (As, Sb) mediated homoepitaxial growth on Si (111) are examined by scanning tunneling microscopy and extensive ab initio calculations of Si-n clusters (nless than or equal to12). The results reveal the different microscopic behavior of the two surfactants: On As-covered Si (111), one exclusively finds two-dimensional islands with double-layer height which show the (1x1) terrace structure. On Sb-covered Si (111), the islands show two different reconstructions: at the rim of the islands a (1x1) structure appears, while in the center the (root3xroot3) terrace structure is observed.