Study on Effect of Via Contour Distortion on Via Micro-void Formation in 45nm-node Process

Abstract

We have investigated micro-void formation mechanism in vias at 45 nm-node using OBIRCH method and SEM analysis, and found that micro-void formation is induced by via contour distortion. We have also clarified the correlation between edge roughness of a via pattern and micro-void formation. From this, we conclude that via edge roughness suppression is the key technology for robust interconnects fabrication in 45 nm-node and beyond.