In order to clarify the resistive switching and failure mechanisms in Al/amorphous-TiO2/Al devices, an investigation was made of the microscopic change in amorphous titanium oxide films and interface layers at film deposition temperatures. For low-temperature (<150C) samples, the thickness of the top interface layer decreased due to the dissociation of a top interface layer via the uniform migration of oxygen vacancies. Meanwhile, for high-temperature samples, crystalline TiO phases emerged in the failed state; implying the formation of conducting paths from the local clustering of oxygen vacancies in nonhomogeneous titanium oxide film.

Direct Observation of Microscopic Change Induced by Oxygen Vacancy Drift in Amorphous TiO2 Thin Films. H.Y.Jeong, J.Y.Lee, S.Y.Choi: Applied Physics Letters, 2010, 97[4], 042109