Effects of silica abrasive size on sapphire CMP performances and their removal mechanisms

The effects of silica abrasive size on sapphire CMP performances have been studied. We find that MRR by 10 mn silica slurry could appear rather high, approaching to two thirds of that by 100 mn silica slurry. The removal mechanisms of sapphire using different sizes silica have been investigated using atomic force microscopy (AFM) measurements through observing the variations of atomic step morphology on the wafer surface.