Chemical-mechanical polishing of sapphire by polishing suspension based on aerosil

Abstract

The conditions for the optimal balance among the degree of agglomeration of aerosil in the polishing suspension, removal rate, and the quality of the polished sapphire surface under chemical-mechanical polishing (CMP) with the polishing suspension contained surfactants at different pH were determined. It was determined that these conditions depend on the crystallographic orientation of the sapphire surface. Surface roughness Ra 0.2-0.4 nm and the optical quality class 20/10-40/20 (USA MIL O 13830) was obtained for orientations (0001), (11-20), and (10-12) by CMP with the polishing suspension contained the surfactant with OH functional groups, and at optimal value of pH for each orientations.