The sub-5 nm Hf_0.5Zr_0.5O₂ (HZO) thin films have been studied for years; however, they still suffer from challenges including poor ferroelectricity, wake-up effect, and the need for high-temperature annealing. In this paper, the concept and the method of “monolayer engineering” by atomic layer deposition (ALD) are proposed and implemented, which leads to dramatic improvements in the crystallinity and ferroelectricity of the HZO thin film with a thickness of only ∼4 nm at a low annealing temperature of only 370 °C. By substituting one ZrO₂ for one HfO₂ atomic layer, a high ferroelectric remnant polarization (P_r) ∼15 μC/cm² is achieved in the HZO thin film. Moreover, the pronounced ferroelectric characteristics are demonstrated in the pristine state, indicating the nearly wake-up-free property of the HZO layer. This study manifests that the monolayer engineering by ALD enables atomic tailoring to enhance the material and physical properties of nanoscale thin films.

亚 5 纳米 Hf _0.5 Zr _0.5 O ₂ (HZO) 薄膜已研究多年；然而，它们仍然面临着铁电性差、唤醒效应和需要高温退火等挑战。本文提出并实施了原子层沉积（ALD）“单层工程”的概念和方法，在仅 370 °C 的低退火温度。通过用一个 ZrO ₂代替一个 HfO ₂原子层，高铁电剩余极化 ( P _r ) ∼15 μC/cm ²在 HZO 薄膜中实现。此外，在原始状态下表现出明显的铁电特性，表明 HZO 层几乎没有唤醒特性。这项研究表明，ALD 的单层工程使原子剪裁能够增强纳米级薄膜的材料和物理特性。