Direct deposition of Cu/barrier stacks on dielectric/nonconductive layers using supercritical CO2

Metallization in supercritical CO₂ (scCO₂) is a method to form nano-interconnects for future generation LSIs. It has been recognized that metal layers, Cu for instance, grow only on conductive layers thus requires an underlayer or ´activation´ treatment to promote nucleation. Such a layer is formed by a conventional way, which may limit the potential of scCO₂ deposition. The keys to solve this issues are: 1) to develop a way to deposit a conductive barrier layer, and 2) to develop a proper chemistry to deposit the barrier layer directly on dielectric/nonconductive layers from scCO₂. The focus of this work is to form Cu/barrier stacks on dielectric layers using only scCO₂.