A theoretical modeling approach is developed to predict silica-specific instability in chemical-mechanical polishing (CMP) slurries. In CMP, the formation of large agglomerates is of great concern, as these large particles are associated with high defectivity and poor polish performance. The proposed model describes the complex CMP slurry system as a colloid under high non-linear shear conditions. The model diverges from the classic colloidal models by focusing on the following: reaction limited agglomeration (RLA) bounded by silica-specific modes of transitory bonding, and modified DVLO assumptions to include chemical activation and hydrodynamic agglomerate break-up condition evaluation. In order to build physical intuition and predict key model parameters, fundamental studies and novel metrology of agglomerates is performed.
Thesis Supervisor: Professor Duane Boning