Cracks and chipping occur in a high proportion during the production of sapphire substrates, accounting for 5% to 8% of the total. The technology for mass-producing sapphire in China is still very immature, with the cut sapphire wafers having deep processing marks. These marks can easily lead to deep pitting or scratches after polishing. Therefore, CMP polishing technology is required to achieve flatness of the workpiece. Many factors can affect the polishing quality during the process, such as the composition and pH of the sapphire polishing fluid, pressure, temperature, flow rate, rotational speed, and the quality of the polishing pad.

Polishing of sapphire wafers requires high specifications for the polishing fluid material; overly soft abrasives can lead to extended polishing times and unsatisfactory results.

The ideal abrasive for polishing sapphire at present is diamond polishing fluid. The abrasive in the diamond polishing fluid is made from diamond, which boasts a high hardness, and when paired with a sapphire polishing pad, it achieves a rapid polishing rate. For those with stringent requirements for the quality of the polished surface, the use of Jizhi Electronic silica sol polishing fluid is recommended for fine polishing.