Residual stress minimum in nanocrystalline diamond films

摘要

Nanocrystalline diamond films have been deposited on silicon nitride substrates by hot filament chemical vapor deposition. Gas mixtures of CH_4-H_2-Ar were used with variation of the Ar/H_2 ratio in order to study the influence of the Ar content on the formation of nondiamond phases at the grain boundaries and thus in the film residual stress assessed by x-ray diffraction techniques. By varying this ratio it is possible to optimize conditions, decreasing the film's residual stress to a minimum of 0.09 GPa.