Record High Polarization at 2 V and Imprint-Free Operation in Superlattice HfO₂-ZrO₂ by Proper Tuning of Ferro and Antiferroelectricity

Abstract

Neuromorphic computing, inspired by biological intelligence, offers a pathway to revolutionize artificial intelligence (AI) by unifying memory and processing in an energy-efficient, sustainable framework for data-intensive tasks. Ferroelectric (FE) materials have emerged as promising candidates for implementing artificial synapses, yet achieving low-voltage operation in CMOS back-end compatible devices remains a major challenge. In this work, we demonstrate that proper tuning of ferro and antiferroelectric phase in HfO2-ZrO2 (HZO) superlattice based capacitors can lead to imprint-free switching with record switchable polarization (2Pr) of 76 µC/cm2 under an external field of only 2 MV/cm. The sizable remanent polarization of the superlattice HZO further enables linear potentiation and depression with an on/off ratio of 20 within a 3 MV/cm bias window. Under pulsed operation, the devices show robust endurance, either maintaining polarization with less than 10% degradation up to 108 cycles or surviving beyond 109 cycles with recoverable fatigue. By elucidating two distinct fatigue mechanisms, this work highlights strategies for optimizing FE devices to meet the stringent demands of neuromorphic training applications while non-volatile data retention at room temperature also demonstrates their potential for low-power inference applications at the edge.