The effect of cerium precursor agglomeration on the synthesis of ceria particles and its influence on shallow trench isolation chemical mechanical polishing performance

The level of agglomeration in the cerium precursor and its effect on the physicochemical properties of the synthesized ceria particles and how these properties influence shallow trench isolation chemical mechanical polishing (STI CMP) performance were investigated. Two different types of ceria particles were synthesized from cerium precursors of different degrees of agglomeration. The crystallinity and particle size distribution of the synthesized ceria particles were markedly different between these two types of particles. The ceria particles synthesized from agglomerated cerium precursors had a smaller crystallite size than the other particles due to the incomplete decarbonation reaction, which resulted in large agglomerations of particles. The different physical characteristics of the ceria particles resulted in remarkable discrepancies between the STI CMP performances of the ceria slurries, such as the oxide removal rate, the selectivity and the uniformity.