Dispersion and Polishing Mechanism of a Novel CeO2-LaOF-Based Chemical Mechanical Polishing Slurry for Quartz Glass

Abstract

Quartz glass shows superior physicochemical properties and is used in modern high technology. Due to its hard and brittle characteristics, traditional polishing slurry mostly uses strong acid, strong alkali, and potent corrosive additives, which cause environmental pollution. Furthermore, the degree of damage reduces service performance of the parts due to the excessive corrosion. Therefore, a novel quartz glass green and efficient non-damaging chemical mechanical polishing slurry was developed, consisting of cerium oxide (CeO2), Lanthanum oxyfluoride (LaOF), potassium pyrophosphate (K4P2O7), sodium N-lauroyl sarcosinate (SNLS), and sodium polyacrylate (PAAS). Among them, LaOF abrasive showed hexahedral morphology, which increased the cutting sites and uniformed the load. The polishing slurry was maintained by two anionic dispersants, namely SNLS and PAAS, to maintain the suspension stability of the slurry, which makes the abrasive in the slurry have a more uniform particle size and a smoother sample surface after polishing. After the orthogonal test, a surface roughness (Sa) of 0.23 nm was obtained in the range of 50 × 50 μm2, which was lower than the current industry rating of 0.9 nm, and obtained a material removal rate (MRR) of 530.52 nm/min.

Atomic surface of quartz glass induced by photocatalytic green chemical mechanical polishing using the developed SiO2@TiO2 core–shell slurry

“…This observation suggests the successful removal of Na 2 CO 3 and Na 2 SiO 3 species that were generated on the surface of quartz glass after immersion in the polishing slurry. 19 Based on the XPS analysis, we can infer that the following reaction occurs during the PCMP process, 19,32 leading to the oxidation of Si–OH to Si–O–Si : Na 2 CO 3 + H 2 O → 2Na + + HCO 3 − + CO 2 HCO 3 − + H 2 O → H 2 CO 3 + OH − SiO 2 + OH − → (SiO 3 ) 2− + H 2 O …”

“…The formula for calculating the material removal rate (MRR) of the quartz glass is shown in eqn (1). 14,18,19 where Δ m is the mass loss of quartz glasses before and after the polishing process, ρ is the density of quartz glasses (2.2 g cm −3 ), s is the contact area of quartz glasses and an aluminum alloy plate, and t is the polishing time. The quality of quartz glasses before and after the polishing process was measured by using a precision balance (FA124, Shanghai Lichen Instrument Technology Co., Ltd, China).…”

“…The formula for calculating the material removal rate (MRR) of the quartz glass is shown in eqn (1). 14,18,19…”

“…Through an orthogonal experiment, it was found that a smooth surface with a roughness of 0.23 nm was achieved within the 50 × 50 μm 2 area. 19 In addition to incorporating dispersants and other components, modifying the abrasive particles has proven effective in enhancing the chemical mechanical polishing performance. In the case of silicon wafers, the application of APTS or MTMOS modified silica particles improved CMP by optimizing the stability and polishing properties of the particles, leading to a significant improvement in polishing surface quality.…”

Green solvents in battery recycling: status and challenges

“…34 Moreover, strong acids and alkalis are highly corrosive and cause environmental damage. 38 In is worth noting that the solvent is the key to battery hydrometallurgy and one of the cores for the green recycling of battery materials under mild conditions. 39,40 Therefore, exploring green solvents has gained signicant importance in the quest for more environmentally friendly and efficient production methods.…”