Study on the Properties of Silica Colloid Prepared by Different Processes in Silicon Wafer CMP

The properties of nano-silica colloid prepared by different processes in silicon wafer chemical mechanical polishing (CMP) were studied. The different principles of preparing nano-silica colloid by ion exchange, silica hydrolysis and hydrolytic of TEOS were analyzed respectively. The differences in structure, dispersion, density, and surface morphology were compared. Under the same CMP process parameters, silica colloids prepared by three different processes were used for polishing experiments. The results demonstrate that the hydrolysis of TEOS silica colloid is not suitable for CMP due to the network structure, which made the silica colloid as abrasive can not imply sufficient mechanical friction. The colloidal particles prepared by silica hydrolysis are denser, more uniform, with better dispersion and rough surface. The polishing rate of it is higher than that of ion exchange silica in a certain particle size range, and as the diameter increases, the growth increases.