Energy Analysis of High-Energy Neutral Atoms in the Sputtering of ZnO and BaTiO3

Abstract

The time-of-flight method has been employed to investigate the type and energy of high-energy neutral atoms bombarding the substrates in films of ZnO and BaTiO₃ prepared by both DC planar magnetron sputtering and conventional DC diode sputtering. The high-energy neutral atoms are found to be oxygen atoms. The dependence of the flux of high-energy neutral oxygen atoms and negative oxygen ions on the pressure has also been measured for the planar magnetron sputtering of ZnO. It is shown that the high-energy particles bombarding the substrate are composed of neutral oxygen atoms at higher gas pressures ranging above 0.01 Torr, but negative oxygen ions are comparable with neutral oxygen atoms at pressures of the order of 10^-3 Torr. The production mechanism of these energetic oxygen species is discussed.