Interconnection failure caused by bath degradation in copper electroplating and its VM-FDC using mathematical model

This paper describes an interconnection failure in a copper damascene process of a system on chip caused by the plating bath degradation in copper electroplating equipment. By “semimetrics” using EES data and a statistical method, it is clarified that the root cause of the failure is the plating bath degradation. The degradation is caused by a by-product, whose existence is confirmed by analyzing the bath plating using HPLC. Therefore, the degradation in the plating bath causes void formation in a via hole. Moreover, a VM model for the bath plating degradation due to the by-product is developed using a mathematical model. VM-FDC using a mathematical model is performed and the interconnection failure is prevented.