Optical Emission Spectroscopy Measurement of Ar\H2\CH4 RF Plasma for Nano-Crystal Diamond Film Deposition

Ar\H2\CH4 gas mixture was utilized to grow nanocrystal diamond films in a RF plasma enhanced CVD system. CH4\ H2 ratios were changed to study the effect of plasma radicals on the deposit, in which optical emission spectroscopy (OES) was applied to analyze the plasma radicals. It was found that Hα, Hβ, Hγ, CH, C2 were the main radicals in the plasma. Among them, the CH intensity of OES was usually quite strong and increased sharply when the ratio of CH4/H2 was greater than 3%. The intensity of C2 was weak and basically unchanged with the addition of methane. This study can provide a new possible technical application for depositing NCD films.