Cu damascene interconnects with an organic low-k fluorocarbon dielectric deposited by microwave excited plasma enhanced CVD

An organic non-porous low-k dielectric, fluorocarbon (k=2.2), deposited by a new microwave excited plasma enhanced CVD was successfully integrated into Cu damascene interconnects. A practical nitrogen plasma treatment was also developed as a post dry etch process to minimize damage introduction to fluorocarbon in following damascene process. Electrical characteristics of leakage current significantly improved with low effective dielectric constant (k_eff=2.5). Thermal stress test results of both blanket film and Cu damascene lines reveal that the new fluorocarbon film indicates sufficient thermal stability.