In situ observation of oxygen gettering by titanium overlayer on Hf O2 Si O₂ Si using high-resolution Rutherford backscattering spectroscopy

Oxygen gettering by Ti overlayer (2-8 nm) on a Hf O2 (3 nm) Si O2 (1.5 nm) Si (001) structure was investigated using high-resolution Rutherford backscattering spectroscopy. After deposition of a thin Ti layer, the interfacial Si O2 layer is reduced by ∼0.2 nm and the released oxygen is incorporated in Ti layer. Subsequent annealing at 330 °C in UHV causes further reduction by 0.1-0.8 nm depending on the Ti layer thickness. In addition to the reduction of the Si O2 layer, significant oxygen depletion in the Hf O2 layer was observed for thicker Ti layers after annealing.