The sub-monolayer growth of Ag on Si(111)-(7 x 7) surface at temperatures from 420 to 540K was studied. Island densities, size distributions and average number of Ag atoms per occupied half-unit cell 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 half-unit cell 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 half-unit cells. The capacity of a single half-unit cell was found to be ≈18 Ag atoms and the capacity of half-unit cells covered by the large islands was found to be ≈31 Ag atoms on average.

Reconstruction Determined Submonolayer Growth of Ag on Si(111)-(7 x 7) Surface. P.Sobotík, I.Oštádal, P.Kocán: Surface Science, 2002, 507-510, 389-93