Mimic synaptic behavior with a single floating gate transistor: A MemFlash synapse

Memristive devices are promising candidates for artificial synapses in neuromorphic circuits. We provide evidence that a single floating gate transistor operating in a memristive mode can be used to mimic synaptic functionality. To ensure the memristive operation mode, the three-terminal device is reduced to a two-terminal device in such a way that the device resistance varied accordingly to the charge flow through the device during source-drain voltage application. Furthermore, based on Hebbian learning, a synaptic analytical expression for the learning rate of this device is derived. The experimental findings are theoretically supported by a capacitive based model. The presented two-terminal MemFlash-synapse can be considered as a potential substitute for any memristive synapses in neuromorphic circuits, cross bar arrays, or reconfigurable logics, and is compatible with state-of-the-art Si-fabrication technology.