Particle size dependence of nanoclustered ceria abrasives on surface activity and chemical mechanical planarization performance

• Published in: Applied surface science 2024-08, Vol.663, p.160123, Article 160123
• Main Authors: Kim, Na-Yeon, Hwang, Uiseok, Sung, Jaeuk, Park, In-Kyung, Kim, Taesung, Suhr, Jonghwan, Nam, Jae-Do
• Format: Article
• Language: English
• Subjects: Cerium oxide; Chemical mechanical planarization; Crystallinity; Removal rate; Semiconductors; Surface activity
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2024.160123

[Display omitted] •Surface characteristics of spherical nanoclustered (NC)-ceria nanoparticles (NPs) with varying diameters were investigated.•NC-ceria NPs exhibited a high specific surface area and surface activity (i.e., Ce3+/Ce4+).•The smallest NC-ceria NP slurry achieved the highest SiO2 removal rate in the chemical mechanical planarization process. The particle size of cerium oxide (ceria) abrasives plays a crucial role in the design and development of advanced self-stopping slurries for the chemical mechanical planarization (CMP) process in semiconductor device manufacturing. However, a lack of ceria nanoparticles (NPs) with a narrow size distribution and uniform shape poses challenges in investigating the fundamental principles of the relationship between abrasive size and CMP performance. In this study, we thoroughly investigated the effect of ceria NP size on the removal rate (RR) of silicon oxide using uniform-sized nanoclustered (NC) ceria NPs with three diameters: 51.4 nm (NC51), 68.6 nm (NC69), and 108.0 nm (NC108). While all three types of ceria NPs shared a crystallinity of ∼ 70.6 %, they exhibited distinct physicochemical characteristics. As the particle size decreased, the specific surface area and chemical activity (i.e., Ce3+/Ce4+) increased by 155 % and 69 %, respectively. In the CMP process, where direct contact between the abrasives and wafer occurs, the abrasive size influences CMP performance. Experimentally, NC51 achieved the highest RR among the three slurries, along with complex size-dependent contact properties and chemical activities. These experimental results offer significant insights into precise semiconductor manufacturing in a practical manner.