Experimental investigation of a large volume magnetoplasma source based on surface-wave propagation

We examine the basic characteristics (electron temperature and positive ion density) of , Ar and /Ar high-density magnetoplasmas sustained by the propagation of a surface wave at 2.45 GHz under conditions close to electron cyclotron resonance (ECR). The gas pressures investigated are in the 0.1-10 mTorr range. Our experiments show that the dependence of the electron temperature and positive ion density on gas pressure is markedly different in pure and pure Ar. These results can be explained by the molecular and strong electronegative character of with respect to Ar. Furthermore, it is found that the radial profile of the positive ion density presents sharp peaks at the position where the wave electric field is the highest in the reactor. This shape can be explained using a simplified model which takes into account both radial and axial diffusion.