Lee Sanghun, Seo Seunggi, Kim Tae Hyun, Yoon Hwi, Park Seonyeong, Na Seunggyu, Seo Jeongwoo, Kim Soo-Hyun, Chung Seung-Min, Kim Hyungjun
Department of Semiconductor Engineering, College of AI Convergence, Hoseo University, 79 Hoseo-Ro, Baebang-Eup, Asan 31499, Republic of Korea.
Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea.
J Chem Phys. 2025 Mar 28;162(12). doi: 10.1063/5.0257779.
Area-selective atomic layer deposition (area-selective ALD) has been extensively studied because of its versatility in nanotechnological applications. The priority focus in area-selective ALD is to achieve the desired selectivity; thus, most studies to date have been concentrated on the reaction mechanism of ALD on growth/nongrowth substrates or the development of novel methodologies to resolve the challenges associated with its implementation in high-volume manufacturing. In this study, we performed area-selective ALD of SiO2 on SiO2, where SiO2 was not grown on SiNx, and suggested area-selective ALD approaches that could simultaneously enhance selectivity and film quality. An NH3 plasma treatment was applied to functionalize the SiNx surface with more Si-NH bonds, which exhibited low reactivity toward Si precursors. Although the SiO2 surface was also functionalized with Si-NH bonds, it was not fully converted into Si-NH because of its thermodynamic nature at low temperatures. Consequently, the results showed that NH3 plasma pretreatment was effective in increasing selectivity. Therefore, we performed a layer-by-layer NH3 plasma treatment during the ALD of SiO2 to deposit high-quality films without losing selectivity. The SiO2 film was densified, as confirmed by x-ray reflection spectra without nitrogen impurity incorporation. Electrical property measurements of metal-oxide-semiconductor capacitors confirmed that this approach enabled simultaneous selectivity and SiO2 film-quality enhancement.
区域选择性原子层沉积（area-selective ALD）因其在纳米技术应用中的多功能性而受到广泛研究。区域选择性ALD的首要重点是实现所需的选择性；因此，迄今为止的大多数研究都集中在ALD在生长/非生长衬底上的反应机理，或开发新方法以解决其在大规模制造中实施所面临的挑战。在本研究中，我们在SiO₂上进行了SiO₂的区域选择性ALD，其中SiO₂不在SiNₓ上生长，并提出了可同时提高选择性和薄膜质量的区域选择性ALD方法。采用NH₃等离子体处理使SiNₓ表面功能化，形成更多的Si-NH键，这些键对Si前驱体表现出低反应性。虽然SiO₂表面也用Si-NH键进行了功能化，但由于其在低温下的热力学性质，并未完全转化为Si-NH。因此，结果表明NH₃等离子体预处理在提高选择性方面是有效的。因此，我们在SiO₂的ALD过程中进行了逐层NH₃等离子体处理，以沉积高质量薄膜而不损失选择性。X射线反射光谱证实SiO₂薄膜致密化，且没有氮杂质掺入。金属氧化物半导体电容器的电学性能测量证实，这种方法能够同时提高选择性和SiO₂薄膜质量。
