Diamond-like carbon and nanocrystalline diamond film surfaces sputtered by argon cluster ion beams

Abstract

Conventional (monoatomic) ion beam sputtering of solid surfaces is currently used for surface cleaning and concentration depth profiling. Due to ion-surface interactions, however, a modified near-surface layer arises, characterized with the changed composition and chemical bonding. As a consequence, this complicates data interpretation. A lot of efforts have been devoted to eliminate the problem. Now, the most promising method seems to be application of multi atomic or molecular ion beams.In the present contribution we examine the influence of argon cluster ion beam on composition and chemical bonding of diamond-like carbon (DLC) and nanocrystalline diamond (NCD) film surfaces by using high-energy resolution core-level photoelectron spectroscopy (XPS). Particularly, peak widths and hybridization of carbon atoms is evaluated from C 1s lines. The extent of bonding transformation from C sp3 to C sp2 depended on average energy per Ar atom in the clusters. For the energy as low as a few eV per Ar atom the modification is mild. Prime novelty statementThe novelty of the presented research is the examination of the interaction between Argon cluster ion beam with DLC and NCD surfaces via high-energy resolved C 1s photoelectron spectra. Our results show that bonding transformation from C sp3 to C sp2 due to Ar cluster ion beam sputtering was found mild, if the average argon atom energy in clusters is comparable to the bond strength of the surface target atoms.