Effect of Cu barrier from TaN/Ta Deposition barrier(DD) & TaN/Etching/Ta Deposition barrier(DED) on Cu EM reliability

Electromigration(EM) is one of the main failure modes in copper interconnect evaluation. Good barrier step coverage and good ECP Cu gap-filling in the via process have produced better EM performance of copper interconnect, therefore, we did a different Cu barriers reliability discussion, TaN/Ta Deposition barrier(DD) & TaN/Etching/Ta Deposition barrier(DED). In this paper, we analyzed the difference between barriers of DD / DED test results and the process on via upstream (Figure 1-A / 1-B), and the EM effect of the difference between the bottom barrier and sidewall barrier of the DD and DED.