Scanning tunnelling microscopy was used for real-space imaging of the initial interaction of palladium with the Si(111)-(7 x 7) surface at room temperature. The nucleation of silicide was spatially localized and occurred only in the faulted half of the (7 x 7) unit cell. Large-scan-area images were statistically analyzed to determine the sub-surface extension of the silicide nuclei and the nature of growth as a function of coverage and island size. Steps were found to have no influence on the nucleation at this temperature.

Surface Reconstruction and the Nucleation of Palladium Silicide on Si(111). U.K.Köhler, J.E.Demuth, R.J.Hamers: Physical Review Letters, 1988, 60, 2499-502