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

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-degrees) with switching speed less than 20 ns, on current density of 5 x 10(6) A/cm(2), half-bias non linearity of 135x, and cycling endurance exceeding 10(12) cycles.

Automated summary

In this study, we leverage the high-temperature spin-state driven insulator-to-metal phase transition to demonstrate a two-terminal bi-directional selector suitable for cross-point embedded non-volatile memory. The selector devices show electrically triggered abrupt IMT switching across a range of chip operating temperatures, with fast switching speed and high cycling endurance.