Self-limiting processes in thermal atomic layer etching of nickel by hexafluoroacetylacetone
Self-limiting processes in thermal atomic layer etching of nickel by hexafluoroacetylacetone
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DOI：
10.35848/1347-4065/aba9a7
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发表时间：
2020-08
影响因子：
1.5
通讯作者：
Abdulrahman H. Basher;I. Hamada;S. Hamaguchi
中科院分区：
文献类型：
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作者：
Abdulrahman H. Basher;I. Hamada;S. Hamaguchi
在镍的热原子层蚀刻（ALE）中，在升高的表面温度下，六氟乙酰丙酮（hfacH）蚀刻气体除去氧化的薄镍层，当金属镍表面出现时（自限步骤）蚀刻停止。然而，自我限制步骤的原子细节并没有得到很好的理解。通过定期密度泛函理论计算，发现hfacH分子在金属Ni表面上无障碍吸附并倾向于分解，而在NiO表面，它们可以形成挥发性Ni(hfac)2。我们的研究结果阐明了热ALE中自限过程的起源。
In thermal atomic layer etching (ALE) of Ni, a thin oxidized Ni layer is removed by a hexafluoroacetylacetone (hfacH) etchant gas at an elevated surface temperature, and etching ceases when a metallic Ni surface appears (self-limiting step). However, atomistic details of the self-limiting step was not well understood. With periodic density-functional-theory calculations, it is found that hfacH molecules barrierlessly adsorb and tend to decompose on a metallic Ni surface, in contrast to the case of a NiO surface, where they can form volatile Ni(hfac)2. Our results clarify the origin of the self-limiting process in the thermal ALE.