Mass spectrometric and optical emission diagnostics for rf plasma reactors

Mass spectrometric and optical emission studies have been performed on argon discharges in a GEC rf reference reactor. Kinetic-energy distributions for ions produced in the sheath region are broad and exhibit structure, while ions produced in the bulk plasma exhibit narrow, featureless energy distributions. The addition of small amounts of O2 to an argon discharge significantly alters the observed positive-ion kinetic- energy distributions. Optical emission studies indicate increasing spatial non-uniformity in the plasma at higher pressures. Time-resolved optical emission studies indicate a varying relationship between the applied rf voltage and the time-varying optical emission with changing pressure and position between the electrodes.