Chemically Impregnated Abrasives Provide High Planarization Efficiency Copper CMP Slurry

As device sizes decrease, next generation CMP slurries must achieve planarization on increasingly higher aspect ratio structures. Current copper CMP slurries have a limited planarization efficiency (PE) (ratio of step height removed to thickness removed). Without an improvement in PE, CMP is going to become an increasingly expensive and limiting step in the semiconductor manufacturing process. This research is focused on developing a copper CMP slurry containing nano-sized contact release capsules (nano-CRC). Nano-CRC based slurries consist of a core-shell nanoparticle where the mechanical and chemical components are combined into a single entity. Nano-CRC particles made from porous colloidal silica abrasives were impregnated with glycine, and then coated with a polymer to encapsulate the glycine. Initial results have yielded simultaneously high PE and high material removal rate, which will improve planarity and decrease processing costs.