Effect of Pad Surface Micro-Texture on Coefficient of Friction and Removal Rate during Copper CMP Process

Abstract

In this study, 200-mm blanket copper wafers were polished on an IC1010 M-groove pad, which was conditioned by a 3M A2810 disc and Mitsubishi Materials Corporation (MMC) TRD disc. Pad surface contact area and topography were analyzed using laser confocal microscopy and scanning electron microscopy. The MMC TRD disc generated a lot of large near contact areas corresponding to fractured and collapsed pore walls. The fractured and collapsed pore walls partly covered the adjacent pores, making the pad surface more lubricated during wafer polishing and rendering significantly lower coefficient of friction and removal rate than the 3M A2810 disc.