Hf_1–xZ_xO₂ (HZO) is a promising ferroelectric (FE) material with CMOS compatibility, while the TiN/HZO/W metal-ferroelectric-metal structure provides balanced thermal expansion for stacking. In this study, we developed a 7 nm film of HZO with a FE polarization (2P_r) value of ∼43 μC/cm² and cycling endurance of 10⁸ by determining the appropriate oxidation state for a W bottom electrode deposited via atomic layer deposition with a relatively low annealing temperature of 400 °C. To visualize FE uniformity, we used X-ray absorption spectroscopy phase mapping to construct a two-dimensional map of the orthorhombic (O), tetragonal (T), and monoclinic (M) phases of the HZO film. Subsequent orientation- and chemical-state-resolved X-ray analysis revealed that the enhanced FE polarization performance can be attributed to the combined effects of interface strain and oxygen vacancies. Piezoelectric force microscopy verified the switching uniformity of the devices and revealed the electrical characteristics for use in device optimization.

中文翻译：

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通过底部电极的受控氧化来增强 TiN/Hf1–xZrxO2/W 器件中的铁电性能

Hf _{1– x} Z _x O ₂ (HZO) 是一种有前途的铁电 (FE) 材料，具有 CMOS 兼容性，而 TiN/HZO/W 金属-铁电-金属结构为堆叠提供了平衡的热膨胀。在本研究中，我们通过原子层沉积确定 W 底部电极的适当氧化态，开发了 7 nm HZO 薄膜，其 FE 极化 (2P _r ) 值为 ∼43 μC/cm ²，循环耐久性为 10 ⁸退火温度相对较低，为 400 °C。为了可视化 FE 均匀性，我们使用 X 射线吸收光谱相图构建了HZO 薄膜的斜方 ( O )、四方 ( T ) 和单斜 ( M )相的二维图。随后的取向和化学态分辨 X 射线分析表明，有限元偏振性能的增强可归因于界面应变和氧空位的综合影响。压电力显微镜验证了器件的开关均匀性，并揭示了用于器件优化的电气特性。