Ion formation in an argon and argon-oxygen gas mixture of a magnetron sputtering discharge

Abstract

Formation of singly and doubly charged Arq+ and Tiq+ (q=1,2) and of molecular Ar2+, ArTi+, and Ti2+ ions in a direct current magnetron sputtering discharge with a Ti cathode and argon as working gas was investigated with the help of energy-resolved mass spectrometry. Measured ion energy distributions consist of low-energy and high-energy components resembling different formation processes. Intensities of Ar2+ and ArTi+ dimer ions strongly increase with increasing gas pressure. Addition of oxygen gas leads to the formation of positively charged O+, O2+, and TiO+ and of negatively charged O− and O2- ions.