Enhanced chemical mechanical polishing (CMP) performance of porous self-assembled spherical cerium oxide via RE(La/Pr/Nd) doping

With the linewidth of integrated circuits has progressively narrowed, imposing higher demands on the chemical mechanical polishing (CMP) process. Cerium oxide nanoparticles are widely used as abrasives in CMP, with their physical structure and the surface content of Ce 3+ ions and oxygen vacancies directly affecting their CMP performance. Here in, we synthesized La/Pr/Nd doped CeO 2 with the porous self-assembled spherical structures. Doping with La/Pr/Nd reduced the grain size of cerium oxide, increased its specific surface area, decreased the pore size, and increased the pore volume. HR-TEM analysis shows that the porous self-assembled spherical CeO 2 primarily exposes the (111) crystal facet. Additionally, the density functional theory (DFT) calculation, XPS, H 2 -TPR and XANES analyses shown that doping of La/Pr/Nd facilitated the formation of oxygen vacancies and increased the Ce 3+ content on the (111) crystal facet of the CeO 2 . La atoms are more likely to stabilize on the CeO 2 (111) surface compared to Pr and Nd atoms. The CMP results indicated that, The La-CeO 2 exhibited a higher MRR of 338 ± 7.54 nm/min, which is a 35 % increase compared to p-CeO 2 , and achieved superior surface roughness ( Ra  = 0.201 ± 0.010 nm).