Characteristics and the Model of Resistive Random Access Memory Switching of the Ti/TiO 2 Resistive Material Depending on the Thickness of Ti

The effects of the reactive Ti layer on the resistive switching characteristics of TiN/Ti/TiO 2 /TiN resistive random access memory (ReRAM) are investigated. Nitridation at the top region of Ti during reactive sputtering of the TiN layer and oxygen gettering of Ti from TiO 2 make the TiON/TiO 2- x interface. It results in TiO 2 with a higher concentration of oxygen vacancies during metal alloy annealing, resulting in the low-initial-resistance state. This leads to a stable bipolar switching after the first set process. A larger thickness of Ti decreases resistance value in the high-resistance state, which enables the adjustment of on/off resistance ratio.