NUCLEATION AND GROWTH OF PLATINUM AND NICKEL FILMS ON AMORPHOUS-CARBON SUBSTRATES

The nucleation and growth of Pt and Ni films deposited on amorphous carbon (a-C) substrates by ion-beam sputtering (IBS) have been followed from an early stage through to complete substrate coverage. The influence of IBS parameters and substrate temperature T(s) on deposition rate and metal particle (island) size distributions have been measured. Metal island growth is shown to be predominantly two dimensional in character. Soft-x-ray reflectivity measurements on Ni/a-C multilayers detect the single atom layer increments in Ni island thickness t(Ni)' during growth from the initial (critical) value t(Ni)' = 0.87 nm which is consistent with a theoretical 22 atom cluster model. The influence of the metal island growth stages on the soft-x-ray reflectivity of multilayer mirrors is considered.