Investigation the CMP process of 6 H-SiC in H₂O₂ solution with ReaxFF molecular dynamics simulation

To observe the chemical mechanical polishing (CMP) process at the atomic scale, reactive force field molecular dynamics (ReaxFF-MD) was employed to simulate the polishing of 6 H-SiC under three conditions: dry, pure water, and H₂O₂ solution. This study examined the reactants on the surface of 6 H-SiC during the reaction in the H₂O₂ solution, along with the dissociation and adsorption processes of H₂O₂ and water molecules. The mechanisms for atom removal during the CMP process were elucidated. Variations in the number of different bonds over time and changes in the number of amorphous SiC atoms across various environments were analyzed. A comparison was made regarding the surface morphology of SiC after polishing with diamond abrasives in the three distinct environments.The results indicate that H₂O₂ and water molecules can dissociate into -OH, -H, and -O-. Si atoms form Si-C bonds with carbon atoms in the abrasive or connect with carbon atoms via -O- bridges to form Si-O-C for removal. C atoms are primarily removed in the form of carbon chains. Abrasive grinding can promote the dissociation of -H₂O and -OH. Both water and H₂O₂ solutions can mitigate surface structural damage during the polishing process, with the H₂O₂ solution showing superior effectiveness.