Characterization of Microwave Plasma Using Langmuir Probe and Imaging Techniques

A study of a microwave plasma driven at 2.45 GHz is presented. Using Langmuir probe and 2D imaging of the plasma, a mapping of plasma parameters with the size of the plasma in the overdense region is studied. Gas mixtures in the study include Ar, Ar-O₂ and Ar −He at pressures of 0.1-10 Torr. Delivered power to the plasma ranges from 25-150 W. A Langmuir probe is used to obtain electron density and electron temperature. The size of the plasma is obtained using a CCD camera with bandpass filters. The results are also compared to COMSOL and MOOSE simulations.