Abhijit AichAsim SenapatiZhao‐Feng LouYi‐Pin ChenShih‐Yin HuangSiddheswar MaikapMin‐Hung LeeChee Wee Liu2024-08-292024-08-292024-06-27https://scholars.lib.ntu.edu.tw/handle/123456789/720465<jats:title>Abstract</jats:title><jats:p>In this study, the double remnant polarization (2P<jats:sub>r</jats:sub>) is enhanced from ≈2 to 25 µC cm<jats:sup>−2</jats:sup> at a low applied voltage of ±2 V (or from 10 to 35 µC cm<jats:sup>−2</jats:sup> at a voltage of ±4 V) by decreasing the WN<jats:sub>x</jats:sub> interfacial capping layer (ICL) thickness from 6 to 2 nm in a novel Ru/WN<jats:sub>x</jats:sub> ICL/Hf<jats:sub>0.5</jats:sub>Zr<jats:sub>0.5</jats:sub>O<jats:sub>2</jats:sub>(HZO)/TiN structure after annealing at 400 °C in a furnace. This occurs because of the higher orthorhombic (o) plus rhombohedral (r) phases (&gt;70%), which is analyzed by geometrical phase analysis (GPA) of high‐resolution transmission electron microscope (HRTEM) images. An optimized 2 nm WN<jats:sub>x</jats:sub> ICL memory capacitor shows a low coercive field (E<jats:sub>c</jats:sub>) of 1.27 MV cm<jats:sup>−1</jats:sup> and long endurance of &gt; 10<jats:sup>9</jats:sup> cycles (remaining 2P<jats:sub>r</jats:sub> value of 13.5 µC cm<jats:sup>−2</jats:sup>) under a low field stress of ±2 MV cm<jats:sup>−1</jats:sup> and 0.1 µs hold pulse width (or ≈1.67 MHz). Even this long endurance of &gt; 10<jats:sup>9</jats:sup> cycles is obtained by applying a higher stress of ±2 MV cm<jats:sup>−1</jats:sup>, 1 MHz, or 100 kHz. Under ±3 MV cm<jats:sup>−1</jats:sup> stress, the mechanism is caused by m‐phase growth from both the HZO/TiN bottom electrode (BE) and WN<jats:sub>x</jats:sub> ICL/HZO interfaces, which is evidenced by HRTEM images after 2 × 10<jats:sup>7</jats:sup> cycles for the first time.</jats:p>journal article10.1002/admi.202400185