J. Mater. Sci. Technol. ›› 2025, Vol. 227: 164-173.DOI: 10.1016/j.jmst.2024.12.020

• Research article • Previous Articles     Next Articles

Enhanced synaptic properties in HfO2-based trilayer memristor by using ZrO2-x oxygen vacancy reservoir layer for neuromorphic computing

Turgun Boynazarova,1, Joonbong Leea,1, Hojin Leea,b, Sangwoo Leea, Hyunbin Chunga, Dae Haa Ryua, Haider Abbasa, Taekjib Choia,*   

  1. aHybrid Materials Research Center and Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea;
    bDRAM Technology Development, Samsung Electronics, Hwasung 18448, Republic of Korea
  • Received:2024-09-12 Revised:2024-12-05 Accepted:2024-12-08 Online:2025-01-16
  • Contact: *E-mail address: tjchoi@sejong.ac.kr (T. Choi).
  • About author:1These authors contributed equally to this work.

Abstract: Neuromorphic computing devices leveraging HfO2 and ZrO2 materials have recently garnered significant attention due to their potential for brain-inspired computing systems. In this study, we present a novel trilayer Pt/HfO2/ZrO2-x/HfO2/TiN memristor, engineered with a ZrO2-x oxygen vacancy reservoir (OVR) layer fabricated via radio frequency (RF) sputtering under controlled oxygen ambient. The incorporation of the ZrO2-x OVR layer enables enhanced resistive switching characteristics, including a high ON/OFF ratio (∼8000), excellent uniformity, robust data retention (>105 s), and multilevel storage capabilities. Furthermore, the memristor demonstrates superior synaptic plasticity with linear long-term potentiation (LTP) and depression (LTD), achieving low non-linearity values of 1.36 (LTP) and 0.66 (LTD), and a recognition accuracy of 95.3% in an MNIST dataset simulation. The unique properties of the ZrO2-x layer, particularly its ability to act as a dynamic oxygen vacancy reservoir, significantly enhance synaptic performance by stabilizing oxygen vacancy migration. These findings establish the OVR-trilayer memristor as a promising candidate for future neuromorphic computing and high-performance memory applications.

Key words: HfO2-based trilayer memristor, ZrO2-x oxygen vacancy reservoir, Synaptic plasticity, Non-volatile memory, Neuromorphic computing