Characterization of an Ar/N2 reactive amplified magnetron discharges by Atomic Absorption Spectroscopy and Glow Discharge Mass Spectrometry

The aim of this paper is the characterization of an inductively amplified magnetron discharge running in reactive mode (Ar/N2 gas mixture with titanium target) using Atomic Absorption Spectroscopy and Glow Discharge Mass Spectrometry. The first technique gives access to absolute densities of sputtered metal, usually neutrals. In this paper, ionic titanium densities are also estimated thanks to a pulsed hollow cathode lamp used as optical source for absorption measurements. The second technique deals with the relative behaviour of ions extracted from the plasma. iven pressure, both diagnostic methods are correlated in describing the evolution of the metallic species as the target surface evolves, with the nitrogen content, from the metallic to the poisoned state. The transition is marked by the decrease of titanium neutral (measured by absorption spectroscopy) and relative ionic densities (by mass spectrometry). At 0.7 Pa, the transition happens for a gas mixture containing 6% of nitrogen. It happens for 4% of nitrogen at higher pressure (3.9 Pa). It confirms the validity of mass spectrometry to qualitatively follow titanium neutral density in reactive mode. Nevertheless, both techniques are not correlated in describing the evolution of Ti+ and Ti as the total pressure increases from 0.7 to 9.1 Pa.