A novel ferroelectric memristor enabling NAND-type analog memory characteristics

In this study, we demonstrate an Oxide Memory (OxiM) transistor as a new type of FeFET, provided with dual (top & bottom) gate, which can memorize the channel-conductance with the dynamic range over 10⁵. By using serially-connected OxiM transistors, we were successful in fabricating NAND memory circuit with a retention time over 3.5 months. Since the ferroelectric polarization can be modulated continuously by the gate voltage, note that multi-valued data can be memorized in an OxiM transistor. This present new transistor is implemented by all oxide-based thin films, which include SrRuO₃ (SRO: bottom gate electrode), Pb(Zr,Ti)O₃ (PZT: ferroelectric), ZnO (semiconductor), and SiON (gate insulator).