Diagnostics of inductively amplified magnetron discharges by optical emission, absorption spectroscopy, and Langmuir probe measurements

A direct current (dc) magnetron discharge is coupled to an inductively induced radio frequency (rf) one. The rf part is obtained by means of an induction coil, placed parallel to the cathode. We study the effects of the rf induction coil on the properties of an argon discharge. The discharge is characterized experimentally by optical absorption and emission spectroscopy, Langmuir probe measurements and quartz microbalance. The results are analyzed in order to obtain information on the electrons (density, temperature), ions (density), and excited neutrals (density) as a function of the pressure, the dc and rf powers. It is found that the density of the cathode species is proportional to the dc power while the excitation or ionization degree of the species impinging the substrate is dependent on the rf power.