(115w) Removal of Silica, Copper and Alumina Nanoparticles from Chemical Mechanical Planarization (CMP) Effluents by Ultra and Nano-Filtration

Chemical-Mechanical Planarization or Polishing (CMP) is a critical step used for semiconductors fabrication in microelectronics industry. This step is realized to planning and smoothing the wafer surface by chemical and mechanical forces. One problem in the CMP step is that the effluents could be a very complex mixture of components as copper ions and Si or/and Al nanoparticles. The objectives of this research are study the properties of the CMP wastewater, the interactions between the nanoparticles and the copper, and the removal of particles and copper from effluents. Polishing slurries consist of 5 to 10 percent of very fine particles; surfactants are added to slurries to maintain good stability of the suspended solids in the slurry. The slurries are characterized according to: pH, turbidity (indicative of particle content), particle size distribution, metal ion content, suspended solids, dissolved solids, and chemical oxygen demand. The effluent without copper and particles can be reused in slurry dilutions. Also, the treated CMP effluent can be use in the further treatment to remove organics particles from water. To remove the particles of the effluent filtration technique is used. A significant reduction of copper and turbidity was observed.