Chemical mechanical polishing (or planarization) is the most popular technique for removing the surface irregularities of silicon wafers. Typical CMP slurries consist of a nano-sized abrasive dispersed in acidic or basic solution. A chemical reaction softens the material during mechanical abrasion. The abrasive particles have a size distribution which directly affects critical metrics including rate of removal and wafer defects. Particle size analysis is therefore a key indicator of CMP slurry performance.