Lodha Jayant Kumar, Meersschaut Johan, Pasquali Mattia, Billington Hans, Gendt Stefan De, Armini Silvia
Department of Chemistry, Faculty of Science, KU Leuven, B-3001 Leuven, Belgium.
Semiconductor Technology and System, Imec, Kapeldreef 75, B-3001 Leuven, Belgium.
Nanomaterials (Basel). 2024 Jul 16;14(14):1212. doi: 10.3390/nano14141212.
Area selective deposition (ASD) is a promising IC fabrication technique to address misalignment issues arising in a top-down litho-etch patterning approach. ASD can enable resist tone inversion and bottom-up metallization, such as via prefill. It is achieved by promoting selective growth in the growth area (GA) while passivating the non-growth area (NGA). Nevertheless, preventing undesired particles and defect growth on the NGA is still a hurdle. This work shows the selectivity of Ru films by passivating the Si oxide NGA with self-assembled monolayers (SAMs) and small molecule inhibitors (SMIs). Ru films are deposited on the TiN GA using a metal-organic precursor tricarbonyl (trimethylenemethane) ruthenium (Ru TMM(CO)) and O as a co-reactant by atomic layer deposition (ALD). This produces smooth Ru films (<0.1 nm RMS roughness) with a growth per cycle (GPC) of 1.6 Å/cycle. Minimizing the oxygen co-reactant dose is necessary to improve the ASD process selectivity due to the limited stability of the organic molecule and high reactivity of the ALD precursor, still allowing a Ru GPC of 0.95 Å/cycle. This work sheds light on Ru defect generation mechanisms on passivated areas from the detailed analysis of particle growth, coverage, and density as a function of ALD cycles. Finally, an optimized ASD of Ru is demonstrated on TiN/SiO 3D patterned structures using dimethyl amino trimethyl silane (DMA-TMS) as SMI.
区域选择性沉积（ASD）是一种很有前景的集成电路制造技术，可解决自上而下的光刻-蚀刻图案化方法中出现的对准问题。ASD能够实现抗蚀剂色调反转和自下而上的金属化，例如通过预填充。它是通过促进生长区域（GA）中的选择性生长，同时钝化非生长区域（NGA）来实现的。然而，防止NGA上出现不希望的颗粒和缺陷生长仍然是一个障碍。这项工作展示了通过使用自组装单分子层（SAMs）和小分子抑制剂（SMIs）钝化氧化硅NGA来实现钌膜的选择性。使用金属有机前驱体三羰基（三亚甲基甲烷）钌（Ru TMM(CO)）和氧气作为共反应物，通过原子层沉积（ALD）在氮化钛GA上沉积钌膜。这产生了平滑的钌膜（均方根粗糙度<0.1 nm），每循环生长（GPC）为1.6 Å/循环。由于有机分子稳定性有限且ALD前驱体反应性高，为提高ASD工艺选择性，尽量减少氧气共反应物剂量是必要的，同时仍能保持钌的GPC为0.95 Å/循环。这项工作通过详细分析颗粒生长、覆盖率和密度随ALD循环的变化，揭示了钝化区域上钌缺陷的产生机制。最后，使用二甲基氨基三甲基硅烷（DMA-TMS）作为SMI，在TiN/SiO 3D图案化结构上展示了优化的钌ASD。
