Energetic oxygen ions in the reactive sputtering of the Zr target in Ar+O2 atmosphere

Abstract

In the sputtering of the Zr oxide target of Ar/O2 atmosphere, strong energetic oxygen ions are generated in the sputtering. This is related to the strong oxidation at the Zr surface. The flux of the energetic oxygen ions was estimated in the reactive sputtering of Zr using a probe, constructed here. The dependence of the energetic oxygen ions on the ratio RO2, representing the ratio of the oxygen gas flow to a total gas flow was observed. At the same time, we observed the photoemission intensity from the sputtered Zr atoms in order to monitor the target surface oxidation. The results show that the Zr target is very active in the oxygen atmosphere, and oxidized drastically at the critical point of RO2 where the generation of oxidized islands overcomes the sputtering rate. The flux of the energetic oxygen ions for the Zr target is two or three times stronger than that for the Zn target at the first stage, and ten times at the higher oxygen pressure ratio RO2. The generation of thick oxidized layers on the Zr target gives a strong negative oxygen ions flux.