Target temperature dependence on titanium oxide formation by high-dose oxygen ion implantation into titanium sheets

Abstract

A study has been made of the formation process of TiO and rutile TiO 2 buried in titanium surface layers by O 2 + implantation with high doses. Titanium sheets were implanted with a 150 keV O 2 + beam density of 1–2 μA cm −2 with doses of 2 × 10 17 to 2 × 10 18 O atoms cm −2 at a target temperature ranging from −60 to 300 °C during ion implantation. X-ray diffraction (XRD) patterns of implanted titanium sheets were measured to estimate the formation of titanium oxides. In the case of higher temperature implantation (50 to about 300 °C) XRD patterns showed the formation of rutile TiO 2 structure beyond the dose of 1 × 10 18 O atoms cm −2. In the case of lower temperature implantation (−60 to about −30 °C), XRD patterns of implanted titanium indicated only TiO formation for doses exceeding 1 × 10 18 O atoms cm −2. The structure change from TiO to rutile was not observed in the case of implantation at lower temperature even with high doses. This means that rutile was formed not only by the oxygen atom injection but also by the thermal effect during ion implantation.