Electrical and optical measurements of electron cyclotron resonance discharges in Cl2 and Ar

Electron cyclotron resonance (ECR) discharge plasmas in Cl2 and Ar have been investigated over a pressure range of 0.2–10 mTorr, using microwave interferometry, optical emission spectroscopy, electrostatic probes, and charge collectors. The plasma parameters measured were spatially nonuniform along the magnetic field. The plasma electron density and the plasma potential had their maxima around the ECR region and decreased in going forward the position of the substrate, giving rise to a broadened energy distribution of positive ions incident on the substrate. The plasma density in Ar increased monotonously with increasing pressure, while the density in Cl2 had its maximum around 0.3–0.4 mTorr.