The influence of substrate temperature on the adsorption of sub-monolayer Au on an Si(111)-(7 x 7) surface was investigated using a scanning tunnelling microscope. With a small amount of Au deposited at room temperature, Au atoms formed small clusters located inside the half unit cells of the Si(111)-(7 x 7) surface while most parts of the surface were undisturbed. When the substrate temperature during deposition of the same Au amounts increases from room temperature up to 565C, the small Au clusters grow, coalesce into larger clusters, incorporate Si atoms, and finally formed a (5 x 2) reconstruction. The Si(111)-(5 x 2)–Au reconstruction takes place in the form of island–hole pairs on a terrace, whereas only holes were formed in the upper terrace at a step. Both the islands and the holes display the (5 x 2) reconstruction. The occurrence of the island–hole pairs of the (5 x 2) reconstruction results from the fact that the Si atom density in the (5 x 2) reconstruction was lower than in the (7 x 7) reconstruction.

Influence of Substrate Temperature on Submonolayer Au Adsorption on an Si(111)-(7 x 7) Surface Studied by Scanning Tunnelling Microscopy. L.Zhang, Y.Kim, H.Shim, G.Lee: Journal of Physics - Condensed Matter, 2007, 19[48], 486004 (8pp)