Non-linear effects in Ta sputtering by Aum- ions

Emission of atomic and cluster ions of Ta-n(+) (n = 1-11) has been studied experimentally in sputtering of a Ta target by n Au-m(-) (m = 1-9) cluster ions with energies of 6-21 keV. The high non-additive yield of the secondary ions under molecular bombardment has been observed. Increasing the number of atoms in the bombarding Au-m(-) ions a substantial non-linear increase in the yield of atomic Ta+ ions with quasi-thermal energy has been found. The results obtained have proved experimentally the availability of thermal spikes under cluster bombardment. (C) 2003 Elsevier Science B.V. All rights reserved.