UV nanosecond laser annealing for Ru interconnects

Increasing structural complexity in both 2D and 3D architectures and implementation of new materials in electronic devices is bringing severe limitations of thermal budget. In this context, UV nanosecond laser annealing (UV-NLA) is supposed to be a key thermal process technology owing to its surface localized and very short timescale heating. On the other hand, extension of Cu-based BEOL interconnect technology becomes more and more challenging with very narrow interconnect lines beyond the 7 nm node era. New metals such as Ru start to be explored as an alternative of Cu because of a potential benefit on both line resistance and reliability. But temperatures much higher for these materials than for Cu may be required to improve the line resistance. UV-NLA is therefore a promising process for Ru interconnect performance enhancement. In this paper, benefits of UV-NLA on both Ru blanket and 21 nm half-pitch line structures is studied.