Cu is used as the interconnect metal in CMOS devices, but is facing into significant challenges in its continued use in high-speed ultra-large scale integrated circuits. A diffusion barrier and liner layer are needed for Cu deposition to ensure that it remains conducting but there are significant challenges in Cu deposition in high-aspect ratio structures of vias and trenches. As device dimensions shrink and more complex structures emerge, the volume available for copper interconnect at the transistor levels becomes correspondingly smaller and must still accommodate the barrier, the liner and copper. One solution to these critical issues is to replace copper with alternative metals with low resistivity at the nanoscale that suffer less from these challenges. In this regard, the early transition metals Ruthenium (Ru) and Cobalt (Co) are of high interest as alternative materials for replacing Cu in next generation interconnects. While these metals are potentially facing supply issues, the amount of metal needed for interconnect at the transistor level, so-called level 1 and level 2 interconnect, will be very small, necessitating only limited quantities of both metals so that they are viable candidates for low level interconnect.