CeO2 is one of the most excellent polishing materials and an important rare earth material. It had two stable forms ---Dicerium Trioxide (Ce2O3) and Cerium Dioxide (CeO2). While other forms of oxides are relatively unstable.
Among them, dicerium trioxide (Ce2O3) is sensitive to air and easy to made with cerium dioxide, which is often used as a catalyst. And because the Ce element has a variety of valence states and is easily converted between different valence states ,cerium dioxide is easyoxidize or complex the material on the surface of the glass, so CeO2 is widely used in the polishing of optical glass, mobile phone screen, automotive glass and other glass materials, as well as the chemical mechanical polishing of hard disk and other products.
Ultra-precision polishing is the soul of the modern electronics industry. The demand for flat multi-layer materials depends on ultra-precision polishing tech. In the electronics industry, cerium dioxide, as an efficient polishing abrasive, is widely used in CMP precision polishing.
Compared with other most widely used polishing materials--alumina and silica, cerium oxide has different properties. Cerium dioxide is generally insoluble in alkali. It exhibits amphoteric properties under alkaline conditions and can adsorb both anions and cations.
Among numerous interpretations of the principles of how cerium dioxide works during polishing silicon wafers process, the mainstream explanation is that under the pressure of the polishing machine, CeO2 and SiO2 will react chemically to generate Ce-O-Si bonds, and then form Ce-O-Si(OH)3 bonds. With the pressure and friction of the polishing machine, the Si-O-Si bond breaks, and the SiO2 is Si(OH). The form is thrown away with CeO2.
The Mohs hardness of cerium oxide is 7, which is as same as that of the silicon oxide and lower than that of alumina polishing abrasives. Due to the material hardness and characteristics of cerium oxide, cerium oxide is widely used in precision polishing of electronic materials and various glass materials.
According to the study, before 40% purity ,polishing efficiency of the cerium dioxide polishing powder will be greatly enhanced with the increase of purity. The efficiency of cerium dioxide polishing powder is not only related to purity, but also depends on the particle size of the abrasive. In the processing of various glass and electronic materials, submicron cerium dioxide powder has the most widely used,as it is capable of the requirements of polishing efficiency and surface.