Correlated Oxide Selector for Cross-Point Embedded Non-Volatile Memory

• Published in: IEEE transactions on electron devices 2024-01, Vol.71 (1), p.916-921
• Main Authors: Luo, Yuan-Chun, Khanna, Abhishek, Grisafe, Benjamin, Sun, Jiaxin, Dutta, Sourav, Noskin, Lindsey E., Adamo, Carolina, Mei, Antonio B., Ghosh, Ram Krishna, Colletta, Michael, Holtz, M. E., Gambin, Vincent, Kourkoutis, Lena F., Yu, Shimeng, Schlom, Darrell G., Datta, Suman
• Format: Article
• Language: English
• Subjects: Computer architecture; Correlated oxide selector; cross-point array; embedded non-volatile memory; Liquid crystal on silicon; Microprocessors; Random access memory; Substrates; Switches; Transistors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2023.3338184

Emerging memories such as resistive random access memory (ReRAM) and spin-transfer torque magnetic random access memory (STT-MRAM) are candidates for embedded last-level persistent cache. The maximum attainable array efficiency relies on pairing the storage element with a compatible access device or selector. Here, we leverage the high-temperature spin-state driven insulator-to-metal (IMT) phase transition in a strongly correlated oxide, LaCoO3 (LCO), to demonstrate a two-terminal bi-directional selector suitable for cross-point embedded non-volatile memory. Vertical selectors are fabricated and characterized using epitaxial heterostructures of LCO thin films grown on La0.5Sr0.5CoO3 (LSCO) bottom electrodes. We demonstrate electrically triggered abrupt IMT switching in the selector devices across a range of chip operating temperatures (>85 °C) with switching speed less than 20 ns, on current density of 5\times 10^{{6}} A/cm2, half-bias nonlinearity of 135\times , and cycling endurance exceeding 10^{{12}} cycles.