Understanding and Optimization of Pulsed SET Operation in HfO_x-Based RRAM Devices for Neuromorphic Computing Applications

We use experiments and device simulations to investigate pulsed SET operation of HfO₂-based RRAM devices for their possible use as electronic synapses. The application of a train of identical pulses only allows for an abrupt change of the device current, which is not suitable for synaptic devices. By using simulations, we link the microscopic properties and changes of the conductive filament during the pulsed operation to the measured conductance and its dependence on pulse voltage, width, and number. The results allow us to derive guidelines that we use to design optimized SET pulses (or pulse trains) allowing extending the conventional binary operation of HfO₂-based RRAMs to the multi-level cell operation required by electronic synapses.