Study on Cu Ion Migration Factors and its Mechanism

In this paper, we investigate the potential factors involved in the critical processes from copper chemical and mechanical planarization (CMP) to nitride capping that can lead to copper (Cu) migration into the oxide-nitride interface. Cu migration creates weak points that can accelerate the failure of a MOM capacitor under high voltage, therefore it is important to understand the factors and mechanism of Cu migration to prevent it from happening. Based upon our experimental results, we gain further insight into this phenomenon, and propose a new approach for the mechanism of Cu migration.