Effective thermal characteristics to suppress joule heating impacts on electromigration in Cu/low-k interconnects

We investigated the thermal characteristics of Cu/low-k interconnects to suppress the impact of Joule heating (JH) on electromigration. The thermal time constants in multilayered Cu/low-k interconnects were experimentally investigated for the first time on the basis of the transient thermal response. Furthermore, we analyzed the use of direct radiation through stacked contact/via to suppress the temperature increase from JH. The impact of JH on the critical product of the current density and the line length was also investigated.