Chi-Lin MoHSIN-CHIH LINMIIN-JANG CHEN2025-04-152025-04-152025-04-15https://www.scopus.com/record/display.uri?eid=2-s2.0-85219034792&origin=recordpagehttps://scholars.lib.ntu.edu.tw/handle/123456789/728111In recent years, Hf0.5Zr0.5O2 (HZO) thin films have gained substantial interest due to their exceptional ferroelectric properties and high compatibility with advanced semiconductor technology for non-volatile memory (NVM). However, the ferroelectricity of nanoscale HZO thin films below 10 nm is limited due to the difficulty of increasing the orthorhombic (o-) phase content at the annealing temperatures that can be used in the back-end process, which should not exceed 400 °C. In this study, by introducing the atomic layer annealing (ALA) technology during the deposition of the HZO thin film, significant ferroelectricity is realized with an exceptionally high remnant polarization (2Pr) of ∼68.6 μC/cm2 at a low annealing temperature of 400 °C, which sets a new record 2Pr value for HZO thin films compatible with the back-end process in advanced semiconductor technology nodes. This achievement can be attributed to the facilitated adatom migration enabled by the ALA treatment, which not only enhances the o-phase crystallinity but also allows for the preferred orientation along the polar (002) axis in the out-of-plane direction. Furthermore, the ALA process also eliminates the need for a wake-up process, leading to the realization of wake-up-free ferroelectricity in HZO. The distinguished ferroelectric properties of nanoscale HZO thin films achieved through ALA open up new perspectives in NVM applications.Atomic layer annealingFerroelectricityPreferred orientationRemnant polarizationWake-up-freejournal article10.1016/j.actamat.2025.120855