Mechanism for the formation of molecular clusters under ion sputtering

Abstract

The mechanism for the formation of molecular Si n O 2n+1 − clusters above the surface during the recombination of ions, atoms, and molecules independently sputtered in individual cascades is presented. Clusters form when sputtering products Si, O, SiO and SiO2 (monomers) join the active anion O− successively as a result of pair collisions between them. The joining of monomers involves different combinations of them; in this case, the (Si n O2n+1)− group is formed and consists of monomers with the same masses, but with different monomer compositions in the chain (combinatorial synthesis).