Innovations Enabling the Continued Extendibility of Cu and Post-Cu Damascene BEOL Technologies

• Published in: Proceedings of the IEEE International Interconnect Technology Conference pp. 1 - 3
• Main Authors: Edelstein, D., Jog, A., Nguyen, S., Huang, H., Ghosh, S., Choi, S., Lanzillo, N., Lofaro, M., McDermott, S., Metzler, D., Mignot, Y., Nogami, T., Petrescu, F., Shoudy, M., Silvestre, M., Simon, A., Wangoh, L., Zhang, H., Choi, K.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 02.06.2025
• Subjects: Dielectrics; Industries; Metallization; Reliability engineering; Reviews; Technological innovation; Voltage; Wiring
• ISSN: 2380-6338
• DOI: 10.1109/IITC66087.2025.11075366

We review Cu dual damascene BEOL technology's key historic innovations, and continue forward through present leading-edge into the future. Several recent innovations are combined to extend Cu scaling, preserving industry-leading performance, reliability, and extendibility. These include a novel barrier-like low-k ILD, a novel damascene patterning solution, and a novel Cu metallization process. This combination enables further Cu barrier/liner and aspect-ratio scalings beyond others' predictions. Thus we reduce Cu nanowire RC significantly below the industry trend, starting at 2 nm node (24 nm and 21 nm pitches), while actually raising the highest TDDB and EM reliabilities. We propose a new path for damascene BEOL extendibility beyond Cu, without changing the BEOL integration and tooling infrastructure. For this, we demonstrate the first Rh damascene wiring and are researching post-metal anisotropic conductors, still in an damascene arechtecture and infrastructure. With these advents, we predict a large shift "to the left" (smaller dimensions) in BEOL R and RC crossover projections compared to HAR sub-etched Ru.