Copper Wiring Encapsulation with Ultra-thin Barriers to Enhance Wiring and Dielectric Reliabilities for 32-nm Nodes and Beyond

We successfully encapsulated Cu wiring with an ultra-thin self-forming barrier consisting of MnO and a bi-layer of MnO/Ta. TDDB test showed that the ILDs lifetime increased by a factor of 100 over that of our control sample. The encapsulated Cu wiring increased EM lifetime by a factor of more than 47. For via chains that are vulnerable to thermal stress, the encapsulated Cu wiring showed no SIV failure. The resistance of the encapsulated Cu wiring was 13% lower than that of the control sample. We expect encapsulated Cu wiring to have greater endurance to the electrical and thermal stresses for use in 32-nm nodes and beyond.