Coexistence of non-volatile and volatile characteristics of the Pt/TaO_x/TiN device

Here, we have identified the volatile and non-volatile traits of Pt/TaO_x/TiN device through the various electrical experiments by controlling the compliance current (CC) and determined the availability of this device as a memristor. First of all, the configuration analysis is performed to ensure the structure and thickness of the device. We monitored the volatile resistive switching, which can be facilitated as short-term memory (STM) at a low current level. But in the higher CC, the forming process at the negative bias needs to be accompanied and shows the bipolar resistive switching (BRS), which can be used as non-volatile memory (NVM) within the neuromorphic system. Also, we investigated the conduction mechanism and proved that Space-Charge-Limited-Current (SCLC) dominates the high resistive state in the reset mechanism. The distinct difference between volatile and non-volatile characteristics that appear depending on the CC is shown in the retention test. Finally, we conducted the pattern recognition of the Modified National Institute of Standards and Technology (MNIST) and obtained two pattern recognition accuracy using the potentiation/depression data measured from different BRS types.