Crystallographic orientation dependence of the sputtering yields of nickel and copper for 4-keV argon ions determined using polycrystalline targets

A novel approach for revealing the crystallographic orientation dependences of sputtering yields was developed; this approach used 3D surface profiling and the crystallographic orientation imaging of polycrystalline targets. The sputtering yields of Ni and Cu for normally incident 4-keV Ar⁺ ions were measured over practically all possible crystallographic orientations. They were found to be low around the directions parallel to the [0 0 1] and [1 0 1] axes and around the directions parallel to the $\left(11\overline{1}\right)$ and (0 1 0) planes. The Onderdelinden model for the crystallographic orientation dependences of sputtering yields was extended such that it could include planar channeling. The crystallographic orientation dependence determined experimentally was in semi-quantitative agreement with the dependences calculated using the extended Onderdelinden model; this demonstrated that the non-channeling probability dominantly controls the sputtering yield.