Copper Electrodeposition on Diffusion Barrier Films- A Literature Review

Abstract

Because of its lower electrical and significantly better electromigration and stress migration resistance, copper has emerged as a metal of choice for interconnect fabrication. Among various technologies for copper deposition, the fabrication based on electrochemical deposition has become an industrial standard. However, the electrochemical deposition of copper faces new challenges due to the requirements for the smaller interconnect size, which in turn mandates thinner seed and barrier layers. In this context, the interconnect fabrication issues can be subcategorized in two distinct areas: (1) the relevant properties (resistivity, adhesion, electromigration) of interconnects, specifically those at the barrier/copper interface, and (2) the electrodeposition methods. This paper reviews both areas.