Origin and Innovations of CMP Slurry

This paper reviews how today’s CMP (Chemical Mechanical Polishing) slurries have been innovated and explores ideas for driving further evolution. In early semiconductor polishing, Mechanical Polishing was used, focusing on controlling abrasive particle sizes, leading to the use of alumina abrasives via wet classification. As materials shifted from germanium to silicon and applications transitioned from radios to integrated circuits, research was conducted on the material and size of abrasives to improve polishing accuracy, and silica was finally adopted. Subsequently, in pursuit of higher purity, ultrapure colloidal silica using organic raw materials was introduced in 1985 and became the standard in current semiconductor CMP. The first report on CMP dates back to Schmidt’s 1962 paper. Although the report was based on visual inspection, the approach was validated to be reasonable with today’s inspection technology. CMP achieved further defect reduction by integrating with Clean Technology. Throughout its history, polishing consistently pursued uniform action on surfaces, driving contaminant reduction, and occasionally achieving significant breakthroughs through the combination of diverse technologies. Innovations are born when disparate technologies, evolving independently until a certain point, interact and combine according to market needs.