Based on mechanical processing principles, semiconductor materials engineering, physical chemistry, multiphase reaction and catalysis theory, surface engineering, and fundamental semiconductor chemistry theories, research on the mechanism, kinetic control process, and influencing factors of chemical mechanical polishing (CMP) of silicon single-crystal wafers reveals that CMP is a complex multiphase reaction involving two kinetic processes:
The first is the redox reaction on the substrate surface, where oxidants and catalysts adsorbed on the polishing cloth react with silicon atoms on the substrate surface. This is the main chemical reaction.
The second is the desorption process, where reactants detach from the silicon single-crystal surface, exposing unreacted silicon crystals. This is another crucial process controlling the polishing rate.
The CMP process for silicon wafers is a mechanical polishing process primarily driven by chemical reactions. To obtain high-quality polished wafers, a balance must be achieved between the chemical etching and mechanical abrasion effects. If the chemical etching effect is greater than the mechanical polishing effect, corrosion pits and orange-peel-like ripples will appear on the surface. If the mechanical abrasion effect is greater than the chemical etching effect, a highly damaged layer will form on the surface.