Chemical absorption and interaction mechanisms of β-silicon carbide in chemical mechanical polishing under minimum water quantity lubrication

Chemical Mechanical Polishing (CMP) of silicon carbide (SiC) presents significant challenges due to its high hardness, chemical inertness, and tendency to generate surface and subsurface damage during polishing. These issues are exacerbated under minimum quantity water lubrication (MQWL), where maintaining material removal efficiency and surface quality becomes even more difficult. In this study, molecular dynamics simulations were employed to investigate the CMP process of β-SiC under ultrathin water film lubrication, focusing on the impact of different groove depths and groove widths on material removal rate (MRR), surface roughness, temperature distribution, and residual stress. The results reveal that although increasing groove depth and width reduces MRR, it significantly helps to suppress residual stress and polishing-induced temperature rise, which enhances surface integrity. Quantitatively, the presence of an ultrathin water layer reduced maximum temperature by up to ∼30 % and residual von Mises stress by ∼20 % compared to dry polishing, while achieving smoother surfaces (Root Mean Square global - RMSg improved by ∼10–15 %) especially at groove depths of 8–16 Å and widths of 0–4 Å. Additionally, the water molecules dissociate under mechanical stress into –OH, –H, and –O– groups, with –OH forming strong chemisorption bridges between the SiC substrate and abrasive particles. This interaction promotes chemical bond breaking and contributes to a higher MRR than that observed in non-lubricated environments. These findings not only demonstrate the effectiveness of MQWL in reducing thermal and mechanical damage during CMP but also provide a novel atomic-scale understanding of the chemomechanical synergistic mechanisms under ultrathin water lubrication. The insights gained here may guide the optimization of surface patterning and lubrication strategies for advanced semiconductor CMP applications.