Bottom up Filling Using Electrical Oxidation on Pattern Wafer

Abstract

Cu electroplating has been researched to form the interconnect in integrated circuits. A suppressor and an accelerator are required to accomplish superconformal deposition by electroplating on patterned wafers. Under these conditions, however, it is complicated to control the process and the incorporation of additives in the Cu film increases its overall resistivity. Hence, it is necessary to reduce the amount of additive in the electrolyte. In this paper, gap filling using electrochemical oxidation instead of an accelerator was investigated. This approach resulted in the realization of genuine bottom-up filling.