A robust high-performance electronic synapse based on epitaxial ferroelectric Hf_0.5Zr_0.5O₂ films with uniform polarization and high Curie temperature

Ferroelectric tunnel junction (FTJ) is a promising emerging memristor for the artificial synapse in neuro-inspired computing, which has parallel data processing and low power consumption. The achievement of high-performance electronic synapses requires in-depth exploration of the correlation between the material properties and the device performances as well as the related physical mechanism, which are, however, still quite lacking. We demonstrate here a robust electronic synapse realized by epitaxial ferroelectric Hf_0.5Zr_0.5O₂ (HZO) films with a high Curie temperature of 930 °C and a pristine highly uniform polarization. Based on the optimized ferroelectric HZO film and in-depth understanding of the FTJ mechanism, a robust and high-performance electronic synapse has been successfully realized with high ON/OFF ratio of >500, large continuous conductance regulation range of 1–250 nS and high reliability with the retention of >10⁴ s. Such electronic synapses show good multilevel conductance modulations and synaptic behaviors, such as long-term potentiation (LTP), long-term depression (LTD) and spike-timing dependent plasticity (STDP). A simulated neural network with the synaptic characteristics indicates high recognition accuracy (93.7%) for MNIST database. These results pave a pathway to apply HZO based electronic synapses as the active block in future neuromorphic computing.