Resistive switching behaviors of Ti nano-layer embedded TaOx-based devices

The role of a Ti nano-layer embedded in TaOx-based devices operating with conductive filaments consisting of oxygen vacancies was investigated. The Ti nano-layer was embedded in three different positions: the top interface (Au/TaOx), bottom interface (TaOx/TiN), and both interfaces. The embedded Ti nano-layer serves as not only an oxygen reservoir but also a tunneling barrier in the case of the top interface. The position of the Ti nano-layer and its thickness play important roles in the resistive switching behaviors. In addition, the effect of the current compliance on the resistive switching behaviors was evaluated. The different resistive switching behaviors were investigated using current-voltage sweep measurements and X-ray photoelectron spectroscopy. The non-linear behavior of the low resistance state could be controlled by the top interface and current compliance. The current of the high resistance state could be controlled by the bottom interface. It is noteworthy that only 1.5-nm-thick Ti nano-layer can adjust the non-linear behavior of the low resistance state at top interface and the current of the high resistance state at bottom interface.