Defect-engineering driven imprint enables low-power and high-endurance of antiferroelectric Hf0.3Zr0.7O2 ultra-thin films for nonvolatile memories

초록

Decreasing the operating voltage of (Hf,Zr)O-2-based ferroelectric memories without sacrificing endurance is a longstanding challenge arising from the large coercive field (E-c). Here we demonstrate a defect-engineered, imprinted antiferroelectric in Zr-rich Hf0.3Zr0.7O2 ultrathin films that enables non-volatile, symmetric half-loop operation with 1.25 V low-voltage switching, and endurance to 10(10) cycles. The imprint is established by interfacial oxygen-vacancy accumulation at the top Hf0.3Zr0.7O2 interface, introduced via top-electrode engineering. Chemical analyses confirm a higher fraction of oxygen-deficiency localized at the top interface, while structural analysis reveals well-crystallized tetragonal phases with negligible monoclinic content. The built-in bias shifts the antiferroelectric double loop by -0.62 V, corresponding to Built-in field (E-bi) similar to 0.78 MV cm(-1) and an interfacial fixed-charge density of 8.6 & times; 10(12) cm(-2) with double remanent polarization (2P(r)) of 9.9-14.5 & micro;C cm(2) with < 10% variation even after 10(10) cycles. The effective E-c is reduced to 0.42-0.47 MV cm(-1) during 10(10) switching cycling. Strain analysis indicates reduced in-plane tensile strain and a higher orthorhombic phase fraction in imprinted devices, explaining the strong suppression of wake-up. Switching-kinetics measurements fitted to the nucleation-limited switching model show faster and narrower switching-time distributions. These results establish charged-defect/strain co-engineering as a scalable route to low-voltage, high-reliability Hf1-xZrxO2 memories that relax the traditional speed-endurance trade-off. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

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