Electrode-induced digital-to-analog resistive switching in TaO_x-based RRAM devices

In RRAM devices, electrodes play a significant role during the switching process. In this paper, different top electrodes are used for TaO_y/Ta₂O_5−x/AlO_σ triple-oxide-layer devices. Top electrode-induced digital resistive switching to analog resistive switching was observed. For Pt top electrode (TE) devices, abrupt digital resistive switching behavior was observed, while Al TE devices showed gradual analog resistive switching behavior. Devices with various AlO_σ thicknesses and sizes were fabricated and characterized to evaluate the reliability of the analog resistive switching. The physical mechanisms responsible for this electrode-induced resistive switching behavior were discussed. (paper)