Study on electrochemical mechanical polishing of silicon carbide substrates with controllable material removal behavior

Electrochemical mechanical polishing (ECMP) shows great potential for improving the polishing efficiency and surface quality of silicon carbide (SiC) substrates. However, due to the complexity of its reaction mechanisms, achieving precise material removal from SiC substrates remains challenging. To control the material removal behavior in ECMP, this study investigates the balance between the oxidation layer generated by electrochemical corrosion and the mechanical removal rate by adjusting process parameters. The study explores the material removal mechanisms at different polishing stages, enabling efficient and high-quality controlled removal of SiC. The results show that during the rough polishing stage, the material removal rate (MRR) reached 8.51 μm/h, 2.75 times higher than under non-electric field conditions. In the fine polishing stage, the MRR increased 7.89 times compared to non-electric field conditions, while surface roughness decreased by 12.9%, achieving 0.61 nm with no obvious subsurface damage observed within detection limit. The study emphasizes the importance of controlling the material removal scale at different stages. Rough polishing quickly removes the substrate material through abrasives after oxidation, without introducing a new layer of damage, while fine polishing eliminates the damage from rough polishing, resulting in an ultra-smooth, undamaged substrate surface. This study is crucial for achieving efficient and high-precision manufacturing of SiC substrates.