“…As a global planarization technique, chemical mechanical planarization (CMP) has been widely used for achieving ultraprecision surfaces of a variety of materials, such as silicon wafer, 1 hard disc substrates, 2 sapphire, 3 silicon carbide (SiC), 4 gallium nitride (GaN), 5 silicon nitride (SiN), 6 silicon dioxide film, 7 tantalum, 8 copper, 9,10 etc. Especially, CMP has become the key planarization technology in the field of integrated circuits (ICs).…”