Reliable synaptic plasticity of InGaZnO transistor with TiO₂interlayer

We demonstrate an InGaZnO (IGZO)-based synaptic transistor with a TiO₂buffer layer. The structure of the synaptic transistor with TiO₂inserted between the Ti metal electrode and an IGZO semiconductor channel O₂trapping layer produces a large hysteresis window, which is crucial for achieving synaptic functionality. The Ti/TiO₂/IGZO synaptic transistor exhibits reliable synaptic plasticity features such as excitatory post-synaptic current, paired-pulse facilitation, and potentiation and depression, originating from the reversible charge trapping and detrapping in the TiO₂layer. Finally, the pattern recognition accuracy of Modified National Institute of Standards and Technology handwritten digit images was modeled using CrossSim simulation software. The simulation results present a high image recognition accuracy of ∼89%. Therefore, this simple approach using an oxide buffer layer can aid the implementation of high-performance synaptic devices for neuromorphic computing systems.