Reconstruction determined submonolayer growth of Ag on Si(111)-(7x7) surface

The submonolayer growth of Ag on Si(1 1 1)-(7 x 7) surface at temperatures from 420 to 540 K was studied. Island densities, size distributions and average number of Ag atoms per occupied half-unit cell (HUC) of 7 x 7 reconstruction were investigated. At higher coverage large 2D islands with jagged shapes were observed. A scenario of the growth was outlined, based on the assumptions of existence of saturated Ag islands on the surface which cannot overgrow HUC boundaries by adatom capture. Such a model explains morphology of the large islands as well as the presence of the large amount of small islands formed inside HUCs. The capacity of a single HUC was found to be approximate to18 Ag atoms and the capacity of HUCs covered by the large islands was found to be approximate to31 Ag atoms on average. (C) 2002 Elsevier Science B.V. All rights reserved.