Silicon single chip is one of the main substrate materials for semiconductors. During the production process of silicon single crystals, internal defects may occur due to crystal growth, as well as a decrease in semiconductor yield due to mechanical damage and contamination left during the preparation process. In order to obtain a smooth and flat surface of silicon wafers and improve semiconductor yield, it is necessary to grind and polish the silicon wafers. Grinding can achieve micrometer level machining accuracy on the surface of the wafer, but after grinding, there will still be a certain degree of damage layer on the silicon wafer, which needs to be polished in a polishing machine. Currently, silicon wafer polishing uses silicon dioxide polishing fluid, while other polishing fluids such as chromium oxide, manganese oxide, magnesium oxide, and copper ion are rarely used, and will not be introduced here. Silica polishing solution is generally composed of 50~100nm silica particle sol or gel and alkaline aqueous solution. To improve the surface performance of silicon wafers and stabilize the particle dispersion and suspension of polishing solution, some additives can also be added. The solid concentration of silica in the polishing solution is generally between 2% and 10%. In the polishing process, some require rough polishing and some require fine polishing, so there is a distinction between rough polishing liquid and fine polishing liquid. The particle size of the coarse liquid is slightly larger, and the pH value is generally between 9.0 and 9.5; The particle size of the fine polishing solution is slightly smaller, with a pH value of 10.5~11.0