Evaluation of Slurry Flow in Sapphire-Mechanical Polishing

Effect of Platen Surface Texture on Slurry Flow

Abstract

Sapphire is one of the important compound materials for the light emitting diode, and it is required to improve the high throughput planarization because of realizing the processing cost reduction. In mechanical polishing, the slurry mixed free abrasive grains is supplied to the contact surface between the workpiece and the platen. The mechanical polishing characteristics are affected by the slurry flow in the contact surface between the workpiece and the platen. Hence most of previous studies on the slurry flow were focused only qualitative evaluation based on the observed image, but none of them were demonstrated the quantitative evaluation. In this study, we discuss the effect of the surface roughness and wettability of Cu platen for the polishing characteristics on the slurry flow. As a result, the following points were observed. (I) The slurry flow is affected by the slurry wettability and the surface roughness of the platen. (II) The slurry flow velocity is high in case of the high slurry wettability for the platen. (III) The inflow ratio in the contact surface and its region increase with an increase in the slurry velocity.