Preparation of a novel catalyst (SoFeIII) and its catalytic performance towards the removal rate of sapphire substrate during CMP process

• Published in: Tribology international Vol. 120; pp. 99 - 104
• Main Authors: Xu, Li, Zhang, Xin, Kang, Chengxi, Wang, Rongrong, Zou, Chunli, Zhou, Yan, Pan, Guoshun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2018; Elsevier BV
• Subjects: Aluminum; Aluminum silicates; Burnishing; Catalysis; Catalysts; Chemical-mechanical polishing; Material removal rate; Material removal rate (machining); Novel catalyst; Organic chemistry; Polytypes; Sapphire; Silica; Silicon dioxide; Slurries; Step-terrace structure; Substrates; Surface reaction layer; Transmission electron microscopy; X-ray diffraction; Novel catalyst; Material removal rate; Step-terrace structure; Sapphire; Surface reaction layer
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2017.12.016

Chemical mechanical polishing of sapphire with a novel catalyst (SoFeIII)-based colloidal silicon dioxide has been studied with high resolution transmission electron microscopy and X-ray diffraction. It has been found that a polytype of aluminun trihydroxide is formed on the polished crystal surface when SoFeIII-80 °C catalyst is used, while aluminum silicate hydrate layer is found on the polished sapphire surface when burnished with catalyst-free slurry. And the novel catalyst plays effective performance towards improving the removal rate of sapphire, and its removal rate is 7.21 μm/h, 1.66 times than the material removal rate obtained with catalyst-free slurry. Additionally, the optimum CMP removal by SoFeIII-80 °C yielded an ultra-smooth wafer surface with an average roughness of 0.0543 nm. •A novel SoFeIII catalyst shows remarkable catalytic activity for improving the removal rate of sapphire.•The optimum CMP with SoFeIII catalyst yields a superior surface with the average roughnss of 0.0543 nm.•Activation energies in a catalyst-based slurry are much lower than that in a catalyst-free slurry.•A soft Gibbsite layer generates on the sapphire surface polished with a catalyst-based slurry.