Radial ion energy measurements in an electron cyclotron resonance reactor

A high resolution Fabry-Perot interferoineter has been used to study the translational dynandcs of ions in a divergent field ECR reactor. The degree of radial ion motion in the plasn'ia was characterized through measurements of the Doppler profiles of Ar and Cl emission lines at various operating pressures, optical orientations and itagnetic field configurations. Average translational energies for both Ar and Cl ions increase from 1.0eV to 2.5eV as the pressure is decreased from 2.OmTorr to 0.lmTorr. In addition, the application of a collimating magnetic field in the substrate region has a significant effect on the ion emission linewidth. A small Doppler shift is observed for emission collected along the axis of the reactor providing evidence for directed ion motion out of the source region of the plasma. These observations, coupled with Langmuir probe studies of the ion density and plasma potential suggest that radial electric field variations in the plasma contribute significantly to lateral ion motion.