Lee Seunghwan, Kim Hye-Mi, Baek GeonHo, Park Jin-Seong
Division of Materials Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
Division of Nano-Scale Semiconductor Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Dec 22;13(50):60144-60153. doi: 10.1021/acsami.1c16112. Epub 2021 Dec 8.
In semiconductor production, the technology node of a device is becoming extremely small below 5 nm. Area selective deposition (ASD) is a promising technique for creating improved overlay or self-alignment, remedying a conventional top-down method. However, the conventional materials and process (self-assembled monolayer, polymer and carbon film fabricated by chemical vapor deposition, and spin coating) for ASD are not suitable for highly conformal deposition. Thus, we investigated a new strategy to deposit conformal films in ASD by molecular layer deposition (MLD). The MLD processes were conducted for an indicone film deposited by INCA-1 (bis(trimethysily)amidodiethyl indium) and hydroquinone (HQ), as well as an alucone film deposited by TMA (trimethylaluminum) and HQ. After thermal heat treatment of the MLD films, variations in thickness, refractive index, and constituent elements of the annealed MLD films were investigated. The indicone film was used as an inhibiting layer for ASD and was etchable with a dry-etching process. The reactive ion etching process on annealed indicone film was optimized according to plasma power, gas concentration, and working pressure. Ruthenium (Ru) ALD was then performed on the annealed MLD films to investigate nucleation delaying cycles and inhibiting properties. A patterned substrate with an MLD/Si line was created via the RIE process, which was allowed to observe the selectivity of the annealed MLD films. In addition, a patterned substrate of SiO/annealed indicone/Mo was used to investigate the Ru-selective ALD at the nanoscale. The Ru thin film was selectively deposited on the Mo side-wall surface of a 3D trench structure. The growth of the Ru film was inhibited selectively on an annealed indicone surface of approximately 5 nm.
在半导体生产中，器件的技术节点在5纳米以下正变得极其微小。区域选择性沉积（ASD）是一种有前景的技术，可用于实现改进的覆盖或自对准，弥补传统的自上而下方法。然而，用于ASD的传统材料和工艺（通过化学气相沉积制备的自组装单层、聚合物和碳膜以及旋涂）不适用于高度保形沉积。因此，我们研究了一种通过分子层沉积（MLD）在ASD中沉积保形膜的新策略。MLD工艺针对由INCA-1（双（三甲基硅基）酰胺二乙基铟）和对苯二酚（HQ）沉积的铟酮膜以及由三甲基铝（TMA）和HQ沉积的铝酮膜进行。对MLD膜进行热处理后，研究了退火后MLD膜的厚度、折射率和组成元素的变化。铟酮膜用作ASD的抑制层，可通过干法蚀刻工艺蚀刻。根据等离子体功率、气体浓度和工作压力对退火后的铟酮膜上的反应离子蚀刻工艺进行了优化。然后在退火后的MLD膜上进行钌（Ru）原子层沉积，以研究成核延迟周期和抑制性能。通过反应离子蚀刻工艺创建了带有MLD/Si线的图案化衬底，从而可以观察退火后MLD膜的选择性。此外，使用SiO/退火铟酮/Mo的图案化衬底在纳米尺度上研究Ru选择性原子层沉积。Ru薄膜选择性地沉积在3D沟槽结构的Mo侧壁表面上。在约5纳米的退火铟酮表面上，Ru膜的生长被选择性抑制。
