An investigation was made of the Au-induced nanofaceting of vicinal silicon surfaces tilted from [111] towards [11¯2]. Using samples miscut, by 3.8° and 8°, from [111], respectively, scanning tunnelling microscopy revealed the surface morphology as a function of Au coverage (0.04 to 0.44ML). As expected, the Au adsorption produced dramatic changes in surface morphology on both samples. On the 3.8° sample, it was found that as little as 0.04ML of Au was sufficient to remove the faceting present on the clean surface. As more Au was deposited, 1-dimensional chain structures nucleated at step edges. These chain structures eventually grew to form (775)-Au facets. At 0.17ML, a surface was observed; with Si(111)-(7 x 7) terraces and (775)-Au nanofacets. With more Au, the (111) terraces transformed from a 7 x 7 to a 5 x 2 reconstruction and, at 0.4ML, the sample consisted of Si(111)-(5 x 2)-Au terraces, separated by (775)-Au facets. The morphology of the 8° sample also depended critically upon the Au coverage. Below 0.32ML, all 8° surfaces included (775)-Au nanofacets. Above 0.32ML, the (775)-Au facet was no longer stable and Au was accommodated on the surface via the formation of higher-angle facets with a smaller chain spacing. In both samples, the persistence of the (775)-Au facet reinforced the idea that it represented a low-energy facet on the Au-modified vicinal surfaces.

Au-Induced Nanostructuring of Vicinal Si Surfaces. L.J.Pedri, W.Wu, M.C.Gallagher: Journal of Physics - Conference Series, 2007, 61, 322-6