Investigation the CMP process of 6 H-SiC in H ₂O ₂ solution with ReaxFF molecular dynamics simulation

Abstract

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 H ₂O ₂ solution. This study examined the reactants on the surface of 6 H-SiC during the reaction in the H ₂O ₂ solution, along with the dissociation and adsorption processes of H ₂O ₂ 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 H ₂O ₂ 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 -H ₂O and -OH. Both water and H ₂O ₂ solutions can mitigate surface structural damage during the polishing process, with the H ₂O ₂ solution showing superior effectiveness.