Multilevel resistive switching in TiO2/Al2O3 bilayers at low temperature

• Main Authors: N. Andreeva, A. Ivanov, A. Petrov
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2018-02-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.5019570

We report an approach to design a metal-insulator-metal (MIM) structure exhibiting multilevel resistive switching. Toward this end, two oxide layers (TiO2 and Al2O3) were combined to form a bilayer structure. MIM structures demonstrate stable bipolar switching relative to the resistive state determined by the bias voltage. The resistive state of such bilayer structures can be electrically tuned over seven orders of magnitude. The resistance is determined by the concentration of oxygen vacancies in the active layer of Al2O3. To elucidate a possible mechanism for resistive switching, structural studies and measurements have been made in the temperature range 50–295 K. Resistive switching occurs over the entire temperature range, which assumes the electronic character of the process in the Al2O3 layer. The experimental results indicate that hopping transport with variable-length jumps is the most probable transport mechanism in these MIM structures.