Soft ion impact for surface activation during diamond chemical-vapor deposition on diamond and silicon - art. no. 125327

Extremely low-energy ions with a mean kinetic energy of around 2 eV have be en used for surface activation during diamond chemical-vapor deposition at a pressure of 20 mTorr in an inductively coupled plasma. A qualitative mode l based on a current balance between a positively biased substrate and a su rrounding wall was given to describe the variation of ion energy and flux o nto the substrate. The deposits with polycrystalline morphologies were obta ined on the biased diamond(100) and Si(100) substrates by varying the ion f lux. The ion-enhanced surface migration of hydrocarbon adatoms was demonstr ated by the ion flux dependent morphologies of diamond films grown on diamo nd. A high ion flux resulted in large interisland distance and island size, a low island density, and a low fraction of grain boundary. In contrast, t he concurrently induced disadvantage like surface defects and etch pits was shown by the ion flux dependent morphologies of nanocrystalline diamonds g rown on Si. A high ion flux resulted in nonfacetted crystallites and a high frequency of secondary nucleation. Comprehensive discussion on the role of low-energy ions in the growth kinetics suggests that soft ion impact is pr omising for modifying thermally dominated behaviors of adsorbed radicals an d exploring simple processes.