Evaluation of Size Distribution Measurement Methods for Sub-100 nm Colloidal Silica Nanoparticles and Its Application to CMP Slurry

Various methods such as transmission electron microscopy, scanning electron microscopy, dynamic light scattering (DLS), and scanning mobility particle sizer were utilized to measure size distributions for sub-100 nm colloidal silica. Compared to electron micrographs, hydrodynamic diameter of sample is dependent on its concentration from ~60 nm to ~90 nm and it is difficult to measure the poly dispersed nanoparticles and analyze its own properties due to limitation of DLS method, whereas, nano nebulizer (NN)-SMPS method distinguished two different size nanoparticles (51 nm and 82 nm) perfectly and is considerably stable to alternations of concentration and dispersity.