Suppression of High-Energy Backscattered Particles in Magnetron Plasma Using Cylindrical Cathode

In a conventional argon magnetron source using a planar cathode (target), numerous backscattered high-energy (100–200 eV) argon atoms and ions impinge on a substrate, often causing damage in sputtered films. In order to reduce such energetic particles, a cylindrical magnetron source is proposed where most of the high-energy particles are confined inside a cylindrical cathode with low-energy particles impinge on the substrate outside the cylinder. Ar+ ion energy distributions of planar and cylindrical magnetron sources are measured using a mass spectrometer with an energy analyzer. In the cylindrical magnetron, a marked decrease in the energetic component is observed compared with that in the planar magnetron. A Monte Carlo code is developed to simulate energy distributions of Ar and Ar+ in the cylindrical magnetron source. Simulated Ar+ energy distributions are in good agreement with the measurements, reproducing the experimental results.