An Approach of Piezoelectric-Assisted Chemical Mechanical Polishing Using BaTiO ₃ Abrasives and Hydrogen Peroxide

Current CMP processes still face significant challenges in minimizing or eliminating the use of additional oxidants and/or external energy inputs. In this work, we present a green and highly efficient CMP strategy that ingeniously harnesses the piezoelectric effect of barium titanate (BaTiO3) to enhance the polishing process. A five-factor orthogonal experimental design was employed to systematically investigate the influence of key process parameters on the material removal rate (MRR) during silicon wafer polishing. Through parameter optimization, the process achieved an exceptionally high MRR of 436 nm·min–1, accompanied by an ultralow surface roughness (Ra = 0.253 nm). Under the applied polishing pressure, tetragonal-phase BaTiO3 particles generate reactive oxygen species (ROS) in situ. The addition of a small amount of hydrogen peroxide (H2O2) further amplifies this effect: H2O2 acts not only as a catalytic substrate but also as an electron scavenger, significantly accelerating the formation of a soft and easily removable silicate oxide layer on the silicon surface. Simultaneously, the BaTiO3 particles serve as abrasives, mechanically removing this oxide layer and thereby establishing a synergistic “oxidation–abrasion” mechanism. The mechanism was confirmed by ESR and XPS characterization. Notably, the entire polishing process requires no additional energy input such as heating, light irradiation, or external electric fields and operates efficiently using only the standard mechanical action of conventional CMP equipment. This approach thus offers an innovative, environmentally sustainable, and highly effective solution for global silicon wafer planarization.