Film Characterization of Cu diffusion barrier dielectrics for 90 nm and 65 nm technology node Cu interconnects

Abstract

This paper describes film characterization of Cu diffusion barrier SiC, SiCN and SiCO in detail. Although SiCN and SiCO achieve reduced leakage current and k-value, the biggest challenge is to achieve robust stability in film stress and k value because undesirable N and O doping cause increased film stress and k value after deposition. Fine-tuned SiC makes it possible to greatly reduce leakage current and k value to 3.9. From Bias Temperature Stress (BTS) measurement, our desired SiCN, SiCO and fine-tuned SiC are assured in 10-year durability to electrical Cu diffusion.