Agglomeration characteristic of particles in alumina slurry by addition of chemicals and milling process for Cu CMP

Chemical mechanical polishing (CMP) has been widely accepted for the global planarization of multi-layer structures in semiconductor manufacturing. It is generally known that the implementation of optimum slurry composition is one of the important issues. In this experiment, we observed and analyzed the variation by the addition of chemicals and milling time of Cu CMP slurry. The particle size in slurry has influence on polishing rate and defect. The particles with milling process were assayed with the elapse of time and addition of chemical additives. The results showed that the particle size in slurry became smaller by increasing of bead amount and milling time. Additional milling time was appended to examine agglomeration of particle by milling time. The particle size after milling process became bigger with the increase of time due to absence of dispersion stability. It was confirmed that viscosity and particle size increased sharply with addition of tartaric acid in slurry with alumina-C as abrasive.