Nanophase Technologies Corporation has developed concentrated aqueous dispersions of alumina and ceria nanoparticles as the abrasive components of CMP slurry formulations. The nanoparticles have a uniform particle size and have an extraordinarily high zeta potential. This enables extremely stable aqueous dispersions and allows polishing improvements such as increased planarity with reduced defectivity in general, and greater selectivity during STI polishing applications, to be realized. The physical properties of these nanocrystalline alumina and ceria dispersions will be presented, with particular emphasis on particle characteristics that permit the preparation of concentrated aqueous dispersions with controlled rheology. The manipulation of dispersion pH, including crossing the isoelectric point of the particles, will be presented. Finally, examples of typical particle size distributions for these dispersions will be shown.
展开▼
