Effects of abrasive scratching depth on chemical reaction of SiC substrate

The mechanism of mechanical and chemical interaction in chemical mechanical polishing (CMP) process is still elusive, which has great limitations on the improvement of material removal efficiency of SiC. In this paper, the molecular dynamics simulation was used to study the reaction process between scratched SiC and H₂O₂ solution at different temperatures. The effects of scratching behavior of diamond abrasive on the chemical reactivity of SiC surface were studied, focusing on the types and quantities of reaction groups, the micromechanical properties of SiC surface and the structural phase transition. The simulation results showed that the existence of surface scratches can not only greatly enhance the chemical reactivity of SiC surface, resulting in an increase in the variety of reactive groups and making a promotion to the formation of polyhydroxy-silicon and metasilicic acid structures, but also dramatically reduce its surface nanoindentation hardness and elastic modulus. Additionally, the scratching experiment and the C/Si/O binding energy site obtained by XPS have also verified the enhancement effects of diamond abrasive scratching on the chemical reactivity of SiC surface. The work reveals the effect mechanism of mechanical action on chemical action in detail and helps with deeper understanding of the CMP process of SiC wafer.