Critical role of a double-layer configuration in solution-based unipolar resistive switching memories

Lately, resistive switching memories (ReRAM) have been attracting a lot of attention due to their possibilities of fast operation, lower power consumption and simple fabrication process and they can also be scaled to very small dimensions. However, most of these ReRAM are produced by physical methods and nowadays the industry demands more simplicity, typically associated with low cost manufacturing. As such, ReRAMs in this work are developed from a solution-based aluminum oxide (Al₂O₃) using a simple combustion synthesis process. The device performance is optimized by two-stage deposition of the Al₂O₃ film. The resistive switching properties of the bilayer devices are reproducible with a yield of 100%. The ReRAM devices show unipolar resistive switching behavior with good endurance and retention time up to 10⁵ s at 85 °C. The devices can be programmed in a multi-level cell operation mode by application of different reset voltages. Temperature analysis of various resistance states reveals a filamentary nature based on the oxygen vacancies. The optimized film was stacked between ITO and indium zinc oxide, targeting a fully transparent device for applications on transparent system-on-panel technology.