Chemical Vapor Deposition of Diamond Film by Thermal Plasma Jets

Summary form only given. Diamond films are grown on the molybdenum substrate by a chemical vapor deposition (CVD) using thermal plasma jets mixed with methane and hydrogen. Morphologies of the diamond films grown under various processing conditions, such as substrate temperature and the ratio of hydrogen to methane, are evaluated by scanning electron microscopy (SEM). In addition to the diamond film evaluation, an optical emission spectroscopy (OES) of the thermal plasma jets during the CVD process is performed to examine the chemical and ionizational states of the plasma. Such an OES makes it possible to determine Boltzmann temperature from the selected argon electronic transitions, electron number density from H_beta emission, vibrational and rotational temperatures from C₂ emission (d³Pi_grarra³Pi_u). From the morphology analysis and diagnostic results obtained, the effect of plasma conditions on the diamond film growth will be discussed.