Effects of trivalent lanthanide (La and Nd) doped ceria abrasives on chemical mechanical polishing

• Published in: Powder technology 2022-01, Vol.397, p.117025, Article 117025
• Main Authors: Kim, Eungchul, Lee, Jaewon, Bae, Chulwoo, Seok, Hyunho, Kim, Hyeong-U, Kim, Taesung
• Format: Article
• Language: English
• Subjects: Abrasives; Adhesion force; Cerium oxides; Chemical mechanical polishing; Dopants; Lanthanide-doped ceria; Lanthanum; Material removal rate (machining); Nanoparticles; Neodymium; Oxygen vacancy; Silicon dioxide; Work function; Work functions
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2021.11.069

During chemical mechanical polishing (CMP) for a dielectric layer, Ce3+, which is the active site on the surface of ceria, has a significant effect on the material removal rate (MRR). Ceria nanoparticles were synthesized using a hydrothermal method with different dopant concentrations of lanthanide elements (La and Nd) to increase the concentration of Ce3+. An oxygen vacancy was formed in the ceria doped with the trivalent lanthanide ions, which reduced the surrounding Ce4+ to Ce3+. The concentration of Ce3+ increased up to 32.57% when the amounts of dopants were increased and Nd was doped. The improved reactivities of the particles by doping were verified by measuring the reduction of the work function of the doped ceria nanoparticles and the increase in the adhesion force with SiO2. The polishing performance of Nd-doped ceria at high concentrations achieved an MRR up to 3.62 times higher than those of the comparison groups. [Display omitted] •Via facile hydrothermal method, lanthanide-doped ceria was massively synthesized.•The number of Ce3+ was increased by the formation of oxygen vacancies through doping.•The electrical potential of ceria was enhanced with an increase in the concentration of Ce3+.•The effect of Ce3+ on oxide polishing was discovered from their adhesive interaction.