Role of 1-H Carboxyl Benzotriazole as Corrosion Inhibitor for Cobalt “Bulk Step” Cmp in H2O2 Based Alkaline Slurry

Abstract

Cobalt has been considered as new interconnect metal. In this work, the passivation effect of 1-H Carboxyl Benzotriazole (CBT) on cobalt corrosion during “bulk step” chemical mechanical polishing (CMP) in H2O2 based alkaline slurry was investigated. The result showed that CBT can effectively inhibit the corrosion of cobalt and improve the surface quality after CMP by forming a passivation film on the cobalt surface. Characterization and analysis were given by potential polarization curves, X-ray photoelectron spectroscopy (XPS) and SEM measurements. Meanwhile, the passivation effect of CBT on cobalt was also verified from the mechanical aspect such as working pressure and carrier/platen speeds.