Control of the Kinetic Roughening in Nanostructured Ag Films by Oblique Sputter-Depositions

The roughness is a very important characteristic of a deposited film. Its control is a key issue for technological applications ranging from micro- and nano-electronics, to plasmonics, and biology. In the present work, we use oblique sputtering depositions to tune the roughness of Ag films on mica. In particular, was found to increase from 1.9 ± 0.2 to 10.2 ± 0.9 nm when the deposition angle increases from 0 to 0.84 radians (48 degrees), a regime characterized by the absence of strong shadowing effects. In this regime, the kinetic roughening was justified only on the basis of geometric factors allowing to conclude that σ ≈ σ ₀ + ΔD · sin α, being σ ₀ = σ(0) (the film roughness at normal deposition), and ΔD the standard deviation on the Ag nanostructures (forming the film) mean size D. This simple law was found to be in good agreement with the experimental data.