Realization of atomic-level smooth surface of sapphire (0001) by chemical-mechanical planarization with nano colloidal silica abrasives

In this paper, an innovative study is presented to characterize the chemical-mechanical planarization (CMP) performance on hexagonal sapphire (0001) wafer surface by using colloidal silica (SiO₂) abrasives based slurry with two different particle sizes, which indicates that the value of abrasive size is an important factor to determine the efficiency of CMP and the final planarization quality of wafer surface. The nano SiO₂ abrasives used in this study could perfectly optimize the quality of surface roughness. Furthermore, the authors put forward some suggestions to optimize the CMP efficiency and planarization quality of sapphire wafer.