Effect of inert gas on radicals during diamond film being deposited by HFCVD

The optical emission spectroscopy(OES) is an effective method for plasma diagnosing. In this article, OES was used to in situ measure the hot filament chemical vapor deposition(HFCVD) plasma of acetone/H2 system, acetone/H2/He system and acetone/H2/Ar system respectively. The intensity of radicals, the intensity ratios of CH, H to C2 and the value of electron temperature as a function of inert gas volume fraction were studied. The result shows that the spectrum intensities of radicals increase with the increasing of the inert gas volume fraction, and the influence of argon is much higher than that of helium. The intensity ratios of CH, H to C2 and the value of electron temperature decrease with the increasing concentration of the inert gas in the feed gas. The intensity ratio of CH/C2, H/C2 and the value of electron temperature are higher in the acetone/H2/He system than that in the acetone/H2/Ar system.