**Table 3.**

*Geometric characteristics of the valleys and ridges regular pattern as a function of irradiation dose.*

In conclusion, the interfaces considerably increase the sputtering yield until the ion beam incidence angle reaches a certain critical value at which, the geometric sputtering mechanism is greater than any other sputtering mechanism, and this geometric sputtering promoted the irradiated surface smoothing by a non-diffusional mechanism.

The increased of interdendritic region sputtering yield generated by increased sputtering yield due to grain boundaries sputtering plus interdendritic region sputtering by geometric mechanism promoted the formation of an unevenness between the dendritic and interdendritic region.
