Analysis of material removal behavior and subsurface damage in linear polishing of silicon wafers with tangential vibration on rough surfaces

This research investigated the polishing treatment of silicon wafer rough surfaces using molecular dynamics simulations. The material removal behavior of tangential vibration polishing and linear polishing was analyzed in detail. A molecular dynamics geometric model of tangential vibration polishing for silicon wafers was constructed. The environmental setup and simulation methods were clarified, and the Tersoff, Stillinger–Weber (SW), and Lennard-Jones (LJ) potential functions were used for the simulation. A comparison of the two polishing methods revealed that tangential vibration polishing has significant advantages in material removal. The amount of debris generated in tangential vibration polishing increases by about 35% and is more uniformly distributed. The polishing efficiency is higher, the polishing range expands by about 20%, and surface damage is reduced. In terms of material mechanical properties, tangential vibration polishing caused frictional forces to change periodically, reduced local stress concentration, improved material cohesion, decreased shear strain, and optimized atomic bond structure. Dislocation analysis shows that the peak total dislocation length in tangential vibration polishing is only 20%–25% of that in linear polishing, and no obvious 1/2⟨110⟩ dislocation loops appear. This method can more effectively suppress the generation and development of dislocations. The results provide a theoretical basis for optimizing silicon wafer polishing processes and improving polishing quality.