| Summary: | In this work, we emulate biological synaptic properties such as long-term plasticity (LTP) and short-term plasticity (STP) in an artificial synaptic device with a TiN/TiO<sub>2</sub>/WO<i><sub>x</sub></i>/Pt structure. The graded WO<i><sub>x</sub></i> layer with oxygen vacancies is confirmed via X-ray photoelectron spectroscopy (XPS) analysis. The control TiN/WO<i><sub>x</sub></i>/Pt device shows filamentary switching with abrupt set and gradual reset processes in DC sweep mode. The TiN/WO<i><sub>x</sub></i>/Pt device is vulnerable to set stuck because of negative set behavior, as verified by both DC sweep and pulse modes. The TiN/WO<i><sub>x</sub></i>/Pt device has good retention and can mimic long-term memory (LTM), including potentiation and depression, given repeated pulses. On the other hand, TiN/TiO<sub>2</sub>/WO<i><sub>x</sub></i>/Pt devices show non-filamentary type switching that is suitable for fine conductance modulation. Potentiation and depression are demonstrated in the TiN/TiO<sub>2</sub> (2 nm)/WO<i><sub>x</sub></i>/Pt device with moderate conductance decay by application of identical repeated pulses. Short-term memory (STM) is demonstrated by varying the interval time of pulse inputs for the TiN/TiO<sub>2</sub> (6 nm)/WO<i><sub>x</sub></i>/Pt device with a quick decay in conductance.
|
|---|
