In the mid-1960s, most of the polishing of semiconductor substrates used mechanical polishing, and the resulting mirror surface was extremely damaged. After SiO2 sol and gel polishing was proposed in 1965, chemical mechanical polishing (CMP) technology represented by SiO2 gradually replaced traditional mechanical polishing. Since 1996, with the development of the electronics industry, the demand for silica sol as a raw material for silicon wafer polishing liquid has increased sharply. The so-called polishing agent is composed of SiO2 powder, water, dispersion stabilizer, wetting regulator, pH regulator and surface treatment agent. The mass fraction of SiO2 is up to 60%, and the viscosity of the product is <0.1Pa. S. The gravity sedimentation performance is above 1a. It is a polishing material for CMP technology with excellent performance. It can be used for rough polishing and fine polishing of silicon wafers, as well as Ic processing, and is especially suitable for large-scale integrated circuit multilayer films. The planarization process can also be used for the processing of semiconductor devices, flat-panel displays, polycrystalline modules, micro-motor systems, light guide tubes, etc., such as the subsequent CMP cleaning of wafers.