Correlation between nucleation site density and residual diamond dust density in diamond film deposition

Abstract

Diamond was deposited on substrates pre-etched with diamond powder using either a microwave plasma chemical vapor deposition method or a hot-filament-assisted chemical vapor deposition method. Density of residual diamond dust (i.e., number of diamond particles per unit area on the surface of a substrate) on the pre-etched substrates was determined using field emission scanning electron microscopy, and ranged from 3.3×107 to 6.6×1010 ♯/cm2. The diamond nucleation-site density (i.e., number of nucleation sites per unit area on the surface of a substrate) ranged from 1.5×106 sites/cm2, typical of the deposition on a substrate etched with diamond paste, to 1.1×1010 sites/cm2, sufficient to create nanostructured diamond films. We found that the nucleation site density was about 10% of the residual dust density. Our results also show that the residual diamond dust is the main source of nucleation sites for diamond growth on diamond-etched substrates.