Current conduction and resistive switching characteristics of Sm2O3 and Lu2O3 thin films for low-power flexible memory applications

In this article, the current conduction and resistive switching (RS) behavior in flexible Sm2O3 and Lu2O3 resistive random access memories (ReRAM) are investigated. Amorphous Sm2O3 and Lu2O3 thin films were deposited at room temperature by radio-frequency magnetron sputtering on flexible polyethylene terephthalate substrate. The structural morphologies of the Sm2O3 and Lu2O3 thin films strongly depend on the lattice energy of the oxides. The dominant current conduction mechanism in the oxide layer changes from electrode control Schottky emission in Sm2O3 to bulk controlled space-charge-limited-current in Lu2O3. The barrier height extracted from Schottky emission model is 0.96 eV in Sm2O3 thin film, while the activation energy of traps calculated from the Arrhenius plots is about 0.23 eV in Lu2O3 thin film. Additionally, the Ni/Sm2O3/ITO flexible memory device shows promising RS behavior with very low power of operation (similar to 30 mu W) and small distribution of switching parameters. The memory reliability characteristics of switching endurance, data retention, good flexibility, and mechanical endurance show promising for future memory applications. The filament conduction model is adopted to describe the RS behavior in the Sm2O3 and Lu2O3 ReRAM devices. The improved RS performance in Sm2O3 thin film is attributed to the different physical properties of the thin films. (c) 2014 AIP Publishing LLC.