In this work, we focus on the development of topographically selective deposition (TSD) leading to local deposition on the vertical sidewalls of 3D structures. A proof of concept is provided for the TSD of Ta₂O₅. The TSD process relies on plasma-enhanced atomic layer deposition (PEALD) alternating with quasi-atomic layer etching (ALE). Quasi-ALE involves a fluorination treatment followed by a directional Ar⁺ sputtering step. We show that the fluorination treatment allows a significant decrease in the incident kinetic energy of the subsequent directional Ar⁺ sputtering step. Conversely, when no fluorination step is carried out, TSD requires high incident kinetic energies during the directional Ar⁺ sputtering step, which, in turn, leads to detrimental plasma-induced damage on horizontal surfaces, such as roughness, also promoting by-product redeposition. The benefits and shortcomings of these two TSD approaches—PEALD/quasi-ALE and PEALD/energetic Ar⁺ sputtering—are compared in light of potential bottom-up technological developments.

中文翻译：

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地形选择性沉积：等离子增强原子层沉积/溅射与等离子增强原子层沉积/准原子层蚀刻方法的比较

在这项工作中，我们专注于拓扑选择性沉积（TSD）的发展，从而导致3D结构垂直侧壁上的局部沉积。为Ta ₂ O ₅的TSD提供了概念验证。TSD工艺依赖于等离子体增强的原子层沉积（PEALD）与准原子层蚀刻（ALE）交替进行。准ALE涉及氟化处理，然后进行定向Ar ⁺溅射步骤。我们表明，氟化处理可以显着降低后续定向Ar ⁺溅射步骤的入射动能。相反，当不执行氟化步骤时，TSD在方向Ar ^+时需要高入射动能。溅射步骤继而导致在水平表面上有害的等离子体诱导的损伤（例如粗糙度），也促进了副产物的再沉积。根据潜在的自下而上的技术发展，对这两种TSD方法（PEALD /准ALE和PEALD /高能Ar ⁺溅射）的优缺点进行了比较。