Nanocrystalline nickel thin film growth on various substrates

Nanocrystalline nickel thin films were deposited by magnetron sputtering onto monocrystalline silicon and sapphire, as well as onto fused silica and glass, at room temperature. The film thickness was ranged from 15 to 325 nm, and the deposition time was doubled in each step. The film structure has been studied using grazing incidence small angle X-ray scattering (GISAXS). In thinner films (nominal thickness up to 35nm) island-like structure atop flat film layer is detected for all substrate types, with the island sizes ranging from 4 to 7 nm and inter-island distances varying from 10 to 35 nm. Both the size and inter-island distances sizes varied slightly with the type of the substrate. The flat film contribution to the scattering is also present in the form of fringes, and it is strongest on (amorphous) fused silica substrate, while the film thickness is similar for all the substrate types. In the thicker films (above 35 nm nominal thickness) film to substrate surface correlation is absent. Apart from Porod type scattering, due to the grain agglomeration, additional contribution from few nm sized inhomogeneities, attributed to grain boundaries, was detected.