Chemical-mechanical synergies effects of multi-purpose pH regulators on C-, A-, and R-plane sapphire polishing

The development of sapphire slurry follows the requirements of environmental friendliness, low cost and high efficiency. Therefore, the effects of KOH, aminomethyl propanol (AMP) and arginine (ARG) as pH regulators on the chemical mechanical polishing (CMP) performance of C-, A- and R-plane sapphire were investigated. The results showed that ARG was the most effective, which could increase the removal rates of C-, A- and R-plane sapphire to 5.65 μm/h, 2.80 μm/h and 3.59 μm/h, and reduce the surface roughness Sq to 0.194 nm, 0.161 nm and 0.173 nm, respectively. Mechanical action analysis, XPS, UV-Vis, and theoretical calculations revealed that ARG could improve the mechanical action of CMP and chemical action by acting as a complexing agent to complex with AlOH4−.