Improved retention of nonvolatile bipolar BiFeO3 resistive memories validated by memristance measurements

The transport properties of metal-insulator-metal (MIM) capacitor-like structures have been demonstrated to be sensitive to the metal-insulator interface. BiFeO3 thin films have been grown on Pt/Ti/SiO2/Si substrates with pulsed laser deposition and RF sputtered Au has been used for the top electrode. As quantified by validated memristance measurements, Ar+ irradiation before deposition of the Au top electrode improved the retention of the BiFeO3 –based MIM structures. In principle it is possible to realize multilevel resistive switching with a very large number of intermediate low resistance states in BiFeO3-based MIM structures which is mainly limited by the writing bias.