An Oxide-Based Bilayer ZrO₂/IGZO Memristor for Synaptic Plasticity and Artificial Nociceptor

As artificial intelligence technology advances, memristors are promising to be used as artificial synapses to mimic various biological learning behaviors. In this work, all the memristors are fabricated using 45-nm complementary metal–oxide–semiconductor (CMOS) technology on Si/SiO2 substrate. By inserting a 3-nm indium gallium zinc oxide (IGZO) layer into the Pt/ZrO2/TiN single-layer (SL) memristor, the storage window of the bilayer (BL) memristor is enhanced to 11 times that of the single one. It demonstrates the multilevel conductivity modulating properties of the BL memristors, which can be used to mimic the learning behavior of biological synapses. The Pt/ZrO2/IGZO/TiN memristor has achieved synaptic plasticity, including long-term potentiation/depression (LTP/LTD), spike-timing-dependent plasticity (STDP), and paired-pulse facilitation (PPF). Moreover, the inadaptation, threshold, hyperalgesia, and allodynia characteristics of a nociceptor based on Pt/ZrO2/IGZO/TiN memristor have been accomplished. The BL oxide-based memristor with outstanding synaptic properties and the simulation as an artificial nociceptor provides a feasible application in the future neuromorphic systems for bionic robots.