Atomic-scale insights into the abrasive concentration effects on 6H-SiC removal in CMP

Single-crystal 6H-SiC, a key wide-bandgap semiconductor, requires ultra-precise surface finishing for high-performance electronic and optoelectronic devices. However, chemical mechanical polishing (CMP) of SiC faces significant challenges, as the material removal rate (MRR) is extremely low and the atomic-scale interplay between chemical oxidation and mechanical abrasion is difficult to probe experimentally. This work employs ReaxFF MD simulations combined with systematic polishing experiments to address these challenges. The findings reveal that abrasive concentration critically controls the balance between chemical surface softening and mechanical disruption, determining MRR, surface roughness, and efficiency differences between Si- and C-faces. This study provides novel atomistic insights into the mechanisms of SiC CMP, including the combined effects of chemical and mechanical contributions, and offers guidance for optimizing polishing parameters to improve surface quality and removal efficiency.