Integration and reliability of a noble TiZr/TiZrN alloy barrier for Cu/low-k interconnects

We have investigated TiZr alloy as a new Cu barrier material for low cost and high performance Cu/low-k interconnects. TiZrN ternary nitride was used as a Cu diffusion barrier and TiZr as an adhesion promotion layer. The issue of metal line resistance shift was suppressed using a novel 2-step annealing procedure. Multi-level Cu metal wiring integration was successfully carried out and the enhanced electrical performance of low via resistance with high via yield was obtained. Improved electromigration and stress-induced voiding resistances also have been demonstrated.