For future sub-5 nm technology nodes, the fabrication of semiconductor devices will likely involve the use of area-selective atomic layer deposition (ALD). While area-selective ALD processes have been reported for a variety of materials, most approaches yield a limited selectivity, for example, due to growth initiation at defects or impurities on the non-growth area. Recently, we demonstrated that Ru ALD can be combined with selective etching to achieve area-selective ALD of metal-on-metal with high selectivity. Cycles consisting of an O₂ plasma and an H₂ gas dose were integrated in an ALD-etch supercycle recipe to remove unwanted nuclei on the SiO₂ non-growth area, while obtaining deposition on the Pt or Ru growth area. The current work discusses the challenging compromise that needs to be made between selectivity and net deposition, considering that the material is also removed from the growth area. After investigating deposition between 100 and 200 °C on SiO₂, Al₂O₃, Pt, and Ru in terms of selectivity and net deposition, a substrate temperature of 150 °C was selected since the difference in Ru thickness on Pt and SiO₂/Al₂O₃ was maximum at this temperature, even though still some deposition occurred on the SiO₂ and Al₂O₃ non-growth areas. Different ALD-etch supercycles were studied, using varying O₂ plasma etch times and etch frequencies. The amount of the (undesired) material deposited on the SiO₂ non-growth area was quantified, demonstrating that the selectivity improved for longer O₂ plasma times. On the basis of the results, a simple mathematical description of the nucleation, growth, and etching effects during ALD-etch supercycles is discussed, which can assist the design of future area-selective deposition processes. Overall, this work illustrates how ALD and etch processes can be tuned to simultaneously obtain a high selectivity and a high net deposition of the material at the desired locations.

中文翻译：

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用于区域选择性沉积的原子层沉积和钌的选择性刻蚀：温度依赖性和超循环设计

对于未来的5纳米以下技术节点，半导体器件的制造可能会涉及使用区域选择性原子层沉积（ALD）。尽管已经报道了多种材料的区域选择性ALD工艺，但是大多数方法产生的选择性有限，例如，由于在非生长区域的缺陷或杂质处开始生长。最近，我们证明Ru ALD可与选择性刻蚀结合使用，以高选择性实现金属对金属的区域选择性ALD。将由O ₂等离子体和H ₂气体剂量组成的循环整合到ALD蚀刻超级循环配方中，以去除SiO ₂上不需要的核非生长区，同时在Pt或Ru生长区上沉积。当前的工作讨论了在选择性和净沉积之间需要做出的具有挑战性的折衷，考虑到材料也从生长区域中去除了。根据选择性和净沉积条件研究了SiO ₂，Al ₂ O ₃，Pt和Ru在100到200°C之间的沉积后，由于Pt和SiO ₂上Ru厚度的差异，选择了150°C的衬底温度。即使在SiO ₂和Al ₂ O ₃上仍发生一些沉积，/ Al ₂ O ₃在该温度下也最大。非增长地区。使用不同的O ₂等离子体蚀刻时间和蚀刻频率，研究了不同的ALD蚀刻超循环。对沉积在SiO ₂非生长区域上的（多余的）材料的数量进行了定量，这表明对于更长的O ₂等离子体时间，选择性得到了改善。根据结果​​，讨论了ALD蚀刻超循环过程中成核，生长和蚀刻效应的简单数学描述，这可以帮助设计未来的区域选择性沉积工艺。总的来说，这项工作说明了如何调整ALD和蚀刻工艺，以在所需位置同时获得材料的高选择性和高净沉积。