Fabrication of self-organized nanopatterns by angle-controlled ion sputtering

By using ion sputtering, one can simply induce ripple-like nanoscale patterns on various solid surfaces [Navez, 1962]. On single metal crystals, the main parameters, dominating the pattern formation, are the substrate temperature (Ts) and the ion incidence angle θ [Sekiba, 2002]. An example shows the same Cu(100) surface after Ar⁺ sputtered with different sputtering conditions: (a) Ts ∼ room temperature and θ ∼ 0 degree from surface normal, (b) Ts ∼ 180 K and θ ∼ 70 degree. The size of the sample is Φ8 mm and 1 mm thickness. The current of irradiated ion was ∼ 2 μA, and the sputtering duration is ∼ 10 min in both cases. Thus at relatively higher temperature the formed pattern reflects the symmetry of the substrate due to the anisotropic atom diffusion.