3M Immobilized Micro-Bed Ion Exchange Resin Bed Technology Treatment of PGMEA

The ever-increasing demand for reducing metal content in fluids used for producing advanced nodes in semiconductor industries for either logic or memory devices require new approaches. The standard method of treatment using ion exchange columns [1] are kinetically limited to low ppb while the industry is striving for low ppt that is 1000 times higher reduction. PGMEA is a major solvent for dissolving photosensitive polymers and needs to be free of any ionic metals that could potentially interfere with photolithographic process, diffuse into functional components of the circuit and reduce performance, yield, or device life. In this study, PGMEA with the grade of SEMI G2 was obtained and processed with 3M™ Metal Ion Purifier Immobilized Ion Exchange Resin Monolith technology. One ion exchange chemistry was based on strong acid while the other was based on amino acid chemistry. Twenty metals were measured before and after processing through the immobilized monolith resin structure. Significant reduction in metal content was observed by reducing even the light elements such as sodium and potassium. The process conditions and reduction of each element by both ion exchange chemistries will be discussed.