Evaluation of thermal fatigue damage of 200-nm-thick Au interconnect lines

Thermal fatigue properties of 200-nm-thick Au interconnects with a width of 2 μm were evaluated by applying alternating current. We found that the temperature distribution along the Au interconnect can be described by a simplified one-dimensional equation of heat conduction. The lifetime as a function of thermal cyclic strain range (Δε) for the narrow Au lines follows the conventional Coffin–Manson relationship when Δε ⩽ 0.47%, while the number of cycles to failure extends to an engineering-defined high-cycle fatigue region.