Chemical mechanical polishing of hard disk substrate with α-alumina-g-polystyrene sulfonic acid composite abrasive

α-Alumina-g-polystyrene sulfonic acid (α-Al2O3-g-PSS) composite abrasive was prepared by surface activation, graft polymerization and sulfonation, successively. The composition, dispersibility and morphology of the product were characterized by Fourier transformed infrared spectroscopy, laser particle size analysis and scanning electron microscopy, respectively. The chemical mechanical polishing (CMP) performances of the composite abrasive on hard disk substrate with nickel-phosphorous plating were investigated. The microscopy images of the polished surfaces show that α-Al2O3-g-PSS composite abrasive results in improved CMP and post-CMP cleaning performances than pure α-alumina abrasive under the same testing conditions.