Resistive switching characteristics and failure analysis of TiO₂ thin film deposited by RF magnetron sputtering system

The effect of the postannealing conditions of Ti O₂ thin films deposited using a radio frequency (rf) magnetron sputtering system on their electrical resistive switching characteristics was evaluated in the Pt/Ti O ₂ /Pt structure, and the compositional change of the Ti O₂ thin films after resistive switching failure was investigated. The Pt/Ti O ₂ /Pt structure with polycrystalline Ti O₂ showed a relatively more stable set/reset voltage dispersion and resistance difference between the high resistance state (HRS) and low resistance state (LRS) than those with amorphous Ti O₂. In the energy dispersive X-ray spectroscopy analysis of the Ti O₂ thin film in Pt/Ti O₂ /Pt with reset-stuck failure, in which the resistive switching from the HRS to the LRS failed after repeated resistive switching, the peak intensity of oxygen was significantly decreased compared with that before resistive switching and the decrease of the oxygen content was more noticeable near the top electrode than near the bottom electrode. Consequently, it is considered that the depletion of oxygen in the Ti O₂ thin film after multiple resistive switching cycles by successive voltage sweeping could be one of the main causes of the resistive switching failure phenomenon.