LOW-ENERGY ION-INDUCED DAMAGE OF POLYCRYSTALLINE DIAMOND FILMS

Polycrystalline films with different diamond qualities, prepared by mi crowave chemical vapour deposition (MWCVD) and hollow cathode arc plas ma CVD, were post-treated by normal neon ion bombardment at low energi es (100-1600 eV). The bombardment caused various ion-solid interaction s, resulting in erosion and modification of the diamond surface. In ad dition, the estimation of the etching rates and, consequently, the spu ttering yields, topography and structure modification were studied usi ng scanning electron microscopy and Raman spectroscopy respectively. M ore details of the ion bombardment effects on the films should be inve stigated by cross-sectional transmission electron microscopy in connec tion with electron energy loss spectroscopy at the C K edge. The exper imental results show ion-energy- and film-quality-dependent etching ef fects-up to threshold energies-for surface topography modification. Tw o different algorithms were used to approximate the ion-induced damage depths in polycrystalline diamond from about 10 angstrom (100 eV) up to about 70 angstrom (1600 eV), which are important for layer applicat ion. The results are discussed in the light of a two-step process caus ed by ion bombardment.