Gas phase study and oriented self-standing diamond film fabrication in high power DC arc plasma jet CVD

Gas phase species were diagnosed by in situ spatially resolved OES in high power DC arc plasma jet CVD system. CH, C2, H were found as main species in this deposition plasma environment. Concentration of species was studied with the variation of deposition parameters such as methane concentration, substrate temperature and gas flow rate. C2 was found to be the most sensitive species to deposition parameters. The electron mean temperature was deduced from Hγ/Hβ, and changed little no matter how the deposition parameters varied. Self-standing diamond films with (111) orientation were grown within the modified species atmosphere where the intensity ratio of CH/C2 was higher than 0.41.