Study of central supply methodology for silica-based CMP slurry

For supply quality and reliability concern, a Central Dispense System (CDS) for CMP oxide slurry was recently upgraded by replacing a pressure vacuum vessel dispense unit with maglev centrifugal pumps. This opened up the opportunity to measure various slurry health parameters and CMP defect rates before and after the retrofit and thus determine the influence of the slurry dispense method on slurry health and scratch rates. Most slurry health parameters were unaffected by the retrofit. However, a significant reduction in large particle counts could be observed after replacing the pressure vacuum vessel dispense-units with maglev centrifugal pumps. As a result, slightly lower scratch rates were observed after the retrofit.