Characterization of microwave plasma generated in inhomogeneous magnetic field

Abstract

The paper is devoted to the investigation of the electron cyclotron resonance (ECR) discharge in the decreasing magnetic field in the pressure range from 0.02 Pa to 90 Pa and the absorbed microwave power from 50 W to 400 W. For a discharge characterization we used the floating potentialU _fl and the saturated ion current densityi ⁺_sat . The influence of the substrate holder presence on the plasma microparameters was studied. It was shown that for the substrate holder located near ECR at pressures below 0.3 Pa mainly the magnitude ofU _fl strongly depends on the pressurep, the absorbed microwave powerP _a, and the position of the substrate holder with respect to ECR. The values ofU _fl in the plasma in which the substrate holder is inserted strongly differ from those in the plasma without the substrate holder.U _fl of low pressuresp<0.05 Pa achieves high positive values of about +50 V and this results in sputtering of chamber walls.