Hwang Junghyeon, Kim Chaeheon, Ahn Jinho, Jeon Sanghun
School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-Ro, Yuseong-Gu, Daejeon, 34141, South Korea.
Division of Materials Science and Engineering, Hanyang University, Wangsimni-Ro, Seongdong-Gu, 222, Seoul, Republic of Korea.
Nano Converg. 2024 Dec 16;11(1):58. doi: 10.1186/s40580-024-00461-2.
The advancement in high-performance computing technologies, including quantum and aerospace systems, necessitates components that operate efficiently at cryogenic temperatures. In this study, we demonstrate a hafnia-based ferroelectric tunnel junction (FTJ) that achieves a record-high tunneling electroresistance (TER) ratio of over 200,000 and decade-long retention characteristics. By introducing asymmetric oxygen vacancies through the strategic use of indium oxide (InO) layer, we enhance the TER ratio without increasing off-current, addressing the longstanding issue of low on-current in hafnia-based FTJs. Unlike prior approaches that led to leakage currents, our method optimizes tunneling behavior by leveraging the differential oxygen dissociation energy between InO and hafnium zirconium oxide (HZO). This results in asymmetric modulation of the tunnel barrier, enhancing electron tunneling in one polarization state while maintaining stability in the opposite state. Furthermore, we explore the intrinsic characteristics of the FTJ at cryogenic temperatures, where reduced thermal energy minimizes leakage currents and allows the maximization of device performance. These findings establish a new benchmark for TER in hafnia-based FTJs and provide valuable insights for the integration of these devices into advanced cryogenic memory systems.
包括量子和航空航天系统在内的高性能计算技术的进步，需要在低温下高效运行的组件。在本研究中，我们展示了一种基于氧化铪的铁电隧道结（FTJ），其隧穿电阻（TER）比达到创纪录的200,000以上，并具有长达十年的保持特性。通过战略性地使用氧化铟（InO）层引入不对称氧空位，我们在不增加关电流的情况下提高了TER比，解决了基于氧化铪的FTJ中长期存在的低开电流问题。与导致漏电流的先前方法不同，我们的方法通过利用InO和铪锆氧化物（HZO）之间的差分氧解离能来优化隧穿行为。这导致隧道势垒的不对称调制，增强了一种极化状态下的电子隧穿，同时在相反状态下保持稳定性。此外，我们探索了FTJ在低温下的固有特性，在低温下，热能的降低使漏电流最小化，并使器件性能最大化。这些发现为基于氧化铪的FTJ中的TER建立了新的基准，并为将这些器件集成到先进的低温存储系统中提供了有价值的见解。
