The influence of the calcination time on the physical properties of synthesized ceria particles and their subsequent influence on shallow trench isolation (STI) chemical mechanical planarization (CMP) process performance were investigated. Two different kinds of ceria particles were synthesized by a solid-state displacement method which utilized calcination times of 4 and 6 hours. After the mechanical milling process, both the crystallinity and particle size distribution of the synthesized ceria particles were found to be markedly different between particles formed with different calcination times. Due to incomplete calcination, the ceria particles synthesized with a 4-hour calcination time had a smaller crystallite size than the particles synthesized for 6 hours. This smaller crystallite size ultimately resulted in large agglomerated particles. The differences in the characteristics of the ceria particles further translated into great discrepancies between the STI CMP performances of the ceria slurries made from the two types of particles.

Keywords: ceria; crystallinity; agglomeration; calcination; STI CMP