Electrical Performance and Reliability Investigation of Cosputtered Cu/Ti Bonded Interconnects

Electrical evaluation along with the material analysis and reliability investigation of cosputtered Cu/Ti bonded interconnect in 3-D integration is presented in this paper. Diffusion behavior of cosputtered metals under different bonding ambient is evaluated as well. This paper shows that the bonded structure exhibits several interesting features under atmospheric bonding ambient, including self-formed adhesion layer, Cu-Cu bonding, and Ti oxide sidewall passivation. Electrical and reliability investigations of cosputtered Cu/Ti bonded interconnects show an excellent electrical performance and a high stability under a large variety of reliability tests, indicating the potential of using cosputtered Cu/Ti bonded interconnects for 3-D integration applications.