In this work, a special focus is given to atomic layer etching (ALE) of metals, since this is a relatively new field but is expected to grow rapidly given the major advancements potentially enabled via metal incorporation throughout the manufacturing process of integrated circuits. The impact of John Coburn’s work on the development of ALE processes is analyzed with a focus on ion energy and the neutral-to-ion ratio. To realize atomic precision in removing etch-resistant materials with complex compositions or structures, the surface reactivity would replace etch rate as the parameter of interest to control the chemical contrast needed for selectivity. The desirable etching anisotropy dictates the usage of directional ions. John Coburn’s work on ion-enhanced etching of Si serves as an example that a fine control of ion energy and the neutral-to-ion ratio could be the gateway of reactivity control, which is demonstrated with recent progress on thermal-plasma ALE of Ni. The effect of surface reactivity is studied from first-principle atomistic calculations and confirms the experimental findings.

中文翻译：

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具有各向异性，特异性和选择性的金属原子层蚀刻

在这项工作中，特别关注金属的原子层蚀刻（ALE），因为这是一个相对较新的领域，但是鉴于在整个集成电路的制造过程中通过掺入金属而可能实现的重大进步，因此有望迅速发展。分析了约翰·科伯恩（John Coburn）的工作对ALE工艺发展的影响，重点是离子能量和中性离子比。为了在去除具有复杂组成或结构的耐腐蚀材料中实现原子精度，表面反应性将取代腐蚀速率作为目标参数，以控制选择性所需的化学对比度。理想的蚀刻各向异性决定了方向离子的使用。约翰·科伯恩（John Coburn）在硅的离子增强刻蚀方面的工作可作为一个示例，表明对离子能量的精细控制和中性离子比可成为反应性控制的途径，这在镍的热等离子体ALE的最新研究中得到了证明。 。从第一性原理原子计算研究了表面反应性的影响，并证实了实验结果。