Electrical And OES Diagnostics Of A Magnetized RF Discharge In CH4 Created By A Multihole Cathode Used For a-C:H Deposition

The present work is carried out in the context of the electrical and spectroscopic study of a reactor used for a-C:H deposition. We have studied the influence of the operation system parameters (incident power, pressure) on the self-bias voltage and on the saturation ion current density. The optical emission spectroscopy (OES) is used for the diagnostic by actinometry to determine the relative concentration of species (CH, H) present in the discharge. These measurements have been made over a wide range of incident power inputs of 50-300 W and pressures of 20-100 mTorr. For electrical diagnostic, the results obtained showed that the energy and ion flow bombarding the substrate presented a maximum values at high incident power and decreased with pressure. For spectroscopic diagnostic, the relative concentration of hydrogen and the kinetic of methylidyne radical versus the operation system parameters are studied. The first correlation between electrical and spectroscopic parameters and a-C:H deposition was found, polymer-like thin films with high deposition rates can be obtained at low pressure and with grounded substrate holder.