Non-linear effects in Ta sputtering by Aum− ions

Emission of atomic and cluster ions of Tan+ (n=1-11) has been studied experimentally in sputtering of a Ta target by Aum- (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 Aum- 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.