Soft polymer abrasive slurries for Cu–CMP

Abstract

We are developing novel Cu–CMP slurries based on pure organic particles acting as abrasives to improve polishing defects using functional polymer resin technology. This study investigates the effect of pH of Cu–CMP slurries containing polymer abrasives on the removal rate of Cu, dishing and erosion after CMP. We achieved a dishing of less than 40 nm at pH 8 while maintaining practical removal rates. High removal rate of Cu over Ta and silicon dioxide results in absence of erosion in a dense fabricated structure. We herein explain that the high resistance to defectivity is due to the soft polymer abrasives and a weak alkaline region to form undissolved film of Cu.