Ferroelectric hafnia-based thin films have attracted intense attention due to their compatibility with complementary metal-oxide-semiconductor technology. However, the ferroelectric orthorhombic phase is thermodynamically metastable. Various efforts have been made to stabilize the ferroelectric orthorhombic phase of hafnia-based films such as controlling the growth kinetics and mechanical confinement. Here, we demonstrate a key interface engineering strategy to stabilize and enhance the ferroelectric orthorhombic phase of the Hf_0.5Zr_0.5O₂ thin film by deliberately controlling the termination of the bottom La_0.67Sr_0.33MnO₃ layer. We find that the Hf_0.5Zr_0.5O₂ films on the MnO₂-terminated La_0.67Sr_0.33MnO₃ have more ferroelectric orthorhombic phase than those on the LaSrO-terminated La_0.67Sr_0.33MnO₃, while with no wake-up effect. Even though the Hf_0.5Zr_0.5O₂ thickness is as thin as 1.5 nm, the clear ferroelectric orthorhombic (111) orientation is observed on the MnO₂ termination. Our transmission electron microscopy characterization and theoretical modelling reveal that reconstruction at the Hf_0.5Zr_0.5O₂/ La_0.67Sr_0.33MnO₃ interface and hole doping of the Hf_0.5Zr_0.5O₂ layer resulting from the MnO₂ interface termination are responsible for the stabilization of the metastable ferroelectric phase of Hf_0.5Zr_0.5O₂. We anticipate that these results will inspire further studies of interface-engineered hafnia-based systems.

铁电二氧化铪基薄膜因其与互补金属氧化物半导体技术的相容性而备受关注。然而，铁电正交相是热力学亚稳态的。已经做出各种努力来稳定二氧化铪基薄膜的铁电正交相，例如控制生长动力学和机械限制。_{在这里，我们展示了一种关键的界面工程策略，通过有意控制底部 La 0.67} Sr _0.33 MnO _{3层的终止来稳定和增强 Hf 0.5} Zr _0.5 O ₂薄膜的铁电正交相。我们发现 Hf _0.5 ZrMnO ₂封端的La _0.67 Sr _0.33 MnO _3上的0.5 O ₂薄膜比LaSrO封端的La _0.67 Sr _0.33 MnO ₃上的薄膜具有更多的铁电正交相，但没有唤醒效应。即使 Hf _0.5 Zr _0.5 O ₂厚度薄至 1.5 nm，在 MnO ₂终端上仍观察到清晰的铁电斜方晶系 (111) 取向。我们的透射电子显微镜表征和理论建模揭示了在 Hf _0.5 Zr _0.5 O _{2 处的重建}/La _0.67 Sr _0.33 MnO ₃界面和由MnO _{2界面终止产生的Hf 0.5} Zr _0.5 O ₂层的空穴掺杂是Hf _0.5 Zr _0.5 O _{2 亚}稳态铁电相稳定的原因。我们预计这些结果将激发对界面工程的基于氧化铪的系统的进一步研究。