Experimental study of a radio-frequency Ionized Physical Vapour Deposition process: Contamination by the internal coil

The Ionized Physical Vapour Deposition technique has been developed since 1990 as an improvement of the magnetron sputtering technique to obtain more conformal and dense deposited layers. Amongst the different methods developed to ensure the ionization of the sputtered vapour, the superimposition of an Inductively Coupled Plasma to a magnetron cathode is the most used method. However, the use of an internal radio-frequency (RF) coil to create the additional ionization may lead to contamination of the deposited layers by the material of the coil. We report in this paper a set of experiments that allowed us to control the film deposition pollution. We compared the flux of particles sputtered from the magnetron and deposited on the coil, with the flux of atoms sputtered by ions from the RF coil. In our experiments, the magnetron material is titanium and the coil material is stainless steel.