Self-Rectifying Behavior and Analog Switching under Identical Pulses Using Tri-Layer RRAM Crossbar Array for Neuromorphic Systems

This work analyzes the self-rectifying behavior and the response under identical pulses of tri-layer RRAMs in crossbar arrays to implement the synapse function. Our finding shows that tri-layer RRAMs allow to achieve a stable Low Resistance State (LRS) without complete oxide breakdown. The first RRAM layer works as tunneling barrier allowing to achieve on-state half-bias nonlinearity. Thanks to LRS nonlinearity the power consumption during synaptic programming is reduces of one order of magnitude. Analog switching under identical pulses allows to emulate synaptic plasticity. The multilevel states of conductance have been explained by the enlargement of the conductive filament (CF) in the broken oxide by means of physical based simulations.