ИСТИНА

The spatial distributions of the particles sputtered from solid targets by gas cluster ion beam is important for understanding the mechanisms of sputtering phenomenon as well as for a wide range of technology applications. The unusual angle distributions of the particles sputtered from polycrystalline Mo by gas cluster ions has been shown recently [1]. This distributions differ drastically from so-called lateral distributions shown for Cu and Au experimentally and from computer simulations [2-3]. Molecular dynamics (MD) simulations were performed for the detailed study of the specific features of sputtering by gas cluster ions, in particular the mechanism of particle emission along the normal to the target surface for Mo target. The simulations were carried out for 10-30 keV noble gas clusters with sizes from tens to thousands atoms per cluster impacting Cu an Mo single-crystalline targets. The dependences of the azimuthal and polar angle distributions of sputtered material on the energy and the size of the clusters are presented. A distinct anisotropy is observed in the azimuthal distributions of sputtered Cu and Mo particles. The analysis of these distributions has shown that the observed anisotropy is not similar to Wehner spots which are peculiar to sputtering of the single-crystalline targets by monomer ions. Qualitative difference in sputtering process for Mo and Cu targets has been observed. References [1] V. S. Chernysh, A. E. Ieshkin and Y. A. Ermakov, Appl. Surf. Sci. 326, 285 (2015). [2] N. Toyoda, H. Kitani, N. Hagiwara, T. Aoki, J. Matsuo and I.Yamada, Mater. Chem. Phys. 54, 262 (1998) [3] Z. Insepov and I. Yamada, Nucl. Instr. Meth. Phys. Res. B, 99, 248 (1995)