Copper diffusion and corrosion behavior through the hillock defect found beneath the weak SIN dielectric barrier in dual damascene process

Abstract

Adopting copper as an interconnect metal, many issues related to copper process have happened. Copper hillock is one of those issues. Copper hillock is generated usually during copper dual damascene process. Many researchers had studied the root-cause of copper hillock and various results have been reported. However, the effect of hillock to the actual device is not that much researched yet. Moreover, copper hillock is considered that it does not influence device functioning seriously. The purpose of this work is to clarify the effect of copper hillock to device and provide a solution for reducing it. According to the test results, copper hillock generates the particle of copper-oxide on via hole. Therefore, it is needed that the particle should be removed because it generates copper void by blocking the barrier metal and copper deposition in via hole. From the result of copper hillock reducing test, it can be decreased dramatically by adding anneal and touch up copper CMP processes. Copyright The Electrochemical Society.