Resins used in modern photoresist materials are unique in terms of the portion of the molecular weight distribution that is needed to optimize resolution and development speed. These resins are also limited by the amount of metal ion contaminants that may interfere with circuitry in completed resist layers. Using a liquid-liquid centrifuge, a continuous method of fractionating resin solutions has been developed while a similar methodology was used to remove metal ion contaminants by washing resist solutions with aqueous chelating reagents. Since phenolic resins used in making early generations of resist products were notoriously difficult materials to optimize, they were used to demonstrate the effectiveness of the new continuous methods of fractionation and metal ion removal.

1Currently at Union County College, Springfield Ave., Cranford, NJ 07016