Analysis of optical emission spectroscopy in diamond chemical vapor deposition

Abstract We used optical emission spectroscopy (OES) to study the gas phase chemistry in hot filament chemical vapor deposition (HFCVD) diamond processes. The results show that the methane concentration strongly influenced the intensity ratios of CH, CH+ and Hγ to Hβ, and the effects of the pressure and filament temperature on the relative concentrations of the species were also analyzed. Spatially resolved OES implied that a relative high concentration of atomic H existed near the substrate surface, which is favorable for diamond film growth. Although the relatively high concentrations of CH and CH+ to atomic H are beneficial to increasing diamond nucleation density, they are very harmful to the growth of diamond films.