Machining performance and material removal mechanism of sapphire with novel polishing slurry

Enhancing the interfacial reactivity of polishing slurry is crucial for improving the polishing efficiency and surface quality of sapphire wafers. In this study, a novel green polishing slurry was developed, comprising aminomethyl propanol, xylitol, highly active silica, and deionized water. The processing quality and removal mechanism of this novel green polishing slurry on semi-solid flexible polishing were investigated to achieve ultra-precision, high-efficiency, and environmentally friendly polishing of sapphire wafers. Experimental results demonstrated that the novel green polishing slurry reduced surface roughness by 12.5% and increased the material removal rate by 71.3% compared with traditional polishing slurry. Various analytical techniques, including wear debris analysis, molecular simulation, infrared detection, electrochemical testing, and physical phase detection, were utilized to explore the material removal mechanism. The findings indicated that amino-methyl propanol promotes chemical reactions between the green polishing slurry and sapphire wafers, leading to the conversion of the intermediate product Al(OH)(3) to Al(OH)(4)(-). In addition, the complexation reaction between xylitol and Al(OH)(4)(-) ions during polishing was found to accelerate the removal of surface materials from sapphire wafers, resulting in improved polishing efficiency and surface quality.