Investigation of pad deformation and conditioning during the CMP of silicon dioxide films

An understanding of different aspects of chemical-mechanical polishing (CMP) is sought with emphasis on the polish pad degradation and conditioning during the polishing of silica films. In situ and ex situ conditioning have been compared. In situ conditioning has proven to yield higher removal rates with improved, within wafer uniformities. Some of the factors contributing to the pad deterioration such as the conditioning tool down force, tool speed, and the type of solubilizing ions in the slurry is examined. The dependence on diamond particle sizes, nickel plated on to the conditioning discs, is discussed. The extent of pad wear caused by all of the above factors has been quantitatively determined and presented.