Near-threshold sputtering of MoSi sub 2

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 1999-08, Vol.155 (3), p.272-279
• Main Authors: Soshnikov, I P, Stepanova, M G, Matin, E N, Shakhmin, A L, Khodorkovsky, M A, Bert, N A
• Format: Article
• Language: English
• ISSN: 0168-583X

This paper presents a comprehensive experimental, theoretical and computer simulation study of very low-energy (3-35eV) argon ion sputtering of beta -MoSi sub 2 (0001). Modification of MoSi sub 2 surface composition under low- energy ion bombardment was studied by Auger electron spectroscopy (AES) and X- ray photoelectronic spectroscopy (XPS). The detected changes of surface composition were attributed to preferential sputtering combined with threshold effects. To verify the interpretation, an analytical theory of near-threshold sputtering of compounds is developed which provides a general relation between the sputter threshold energy of target atoms on one side and their atomic masses, surface-binding energies as well with the ion atomic mass on the other side. Elementary mechanisms of near-threshold sputtering are found from the theory and molecular dynamics simulation for MoSi sub 2 . Threshold energies for various mechanisms of Mo and Si sputtering are calculated and used to explain the experimental evidence. From results of the work it is concluded that the experimental study of surface composition changes after near-threshold sputtering provides a radically new approach to investigate surface binding in compounds.