A Novel Method for Measuring the Sizes and Concentrations of 5-500 nm Particles in Colloidal Suspensions

Measurement of the sizes and concentration of particles in colloidal suspensions has been a challenge particularly for suspensions with particles smaller than 100 nanometers. A new measurement technique has been developed that allows for measurement of particles as small as 5 nanometers in these suspensions. This new approach, uniquely combining proven techniques used for counting and sizing aerosol particle size distributions (PSDs) with nebulizer technology, has been developed to measure both particle size and number concentration in concentrated liquid suspensions. The technique has demonstrated the ability to provide unique and useful PSD data for chemical /mechanical planarization (CMP) slurries used extensively in the micro-electronics industry. In addition, the ability to measure filter retention of particles as small as 10 namometers has been demonstrated.