The effects of the initial pulse of tert-butyl iodide as a surfactant in atomic layer deposition of HfO₂ using cyclopentadienyl tris(dimethylamino) hafnium, CpHf(NMe₂)₃, and ozone, O₃, are investigated at 320, 300, and 250 °C. The formation of 2-methylpropene and hydrogen iodide from tert-butyl iodide via elimination reactions is the key idea of our effective approach for improving film conformality, film quality, and leakage current simultaneously. Our predicted growth mechanisms, supported by experimental results, suggest that different blocking probabilities by 2-methylpropene and hydrogen iodide on the top and bottom sides of the trench feature with an aspect ratio of 22.6:1 lead to 10% improvement in film conformality. In addition, ligand exchanges between the Hf precursor and hydrogen iodide lead to effective removal of large portions of carbon-containing ligands, resulting in a significant reduction in carbon residues, 76% at 320 °C and 40% at 250 °C, as evidenced by secondary ion mass spectrometry results. An increase in film density is also observed partly due to better completion of surface reactions between –I of Hf–I and O₃. In terms of electrical properties, a significant improvement of 95% in leakage current is achieved due to the improvement in the film quality when tert-butyl iodide is employed. The deposited HfO₂ film has superior leakage properties of 5.18 × 10⁻⁸ A/cm² at 3 MV/cm, which is below the dynamic random access memory leakage current limit.

中文翻译：

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利用叔丁基碘作为 HfO2 介电薄膜原子层沉积的有效薄膜质量增强剂

的初始脉冲的影响叔丁基碘作为在的HfO的原子层沉积的表面活性剂₂使用环戊二烯基三（二甲氨基）铪，CPHF（NME ₂）₃，和臭氧，O- ₃，在320研究，300，和250℃。由叔生成2-甲基丙烯和碘化氢通过消除反应生成-丁基碘是我们同时改善薄膜保形性、薄膜质量和漏电流的有效方法的关键思想。我们预测的生长机制得到实验结果的支持，表明 2-甲基丙烯和碘化氢在纵横比为 22.6:1 的沟槽特征的顶部和底部的不同阻塞概率导致薄膜保形性提高 10%。此外，Hf 前体和碘化氢之间的配体交换导致有效去除大部分含碳配体，导致碳残留量显着减少，320°C 时为 76%，250°C 时为 40%，如所证明的由二次离子质谱结果。₃ . 在电性能方面，由于使用叔丁基碘时薄膜质量的提高，漏电流显着提高了95% 。沉积的 HfO ₂膜在 3 MV/cm 下具有 5.18 × 10 ^-8 A/cm ^{2 的}优异泄漏特性，低于动态随机存取存储器泄漏电流限制。