Four more potential combined barrier/liner materials, in addition to those Ru-doped surfaces identified in our previous work, were identified using the above approach. These are 25% and 50% Co-doped TaN and 25% and 100% W-doped TaN, although the latter could also be considered as a layer of WN passivation on TaN. This shows clearly that it is possible to tailor the properties of a material through doping in the surface, which in the case of a barrier material like TaN would reduce the overall volume occupied by the barrier/liner without compromising the barrier properties. The selection of potential combined barrier/liner materials identified through our studies is based on materials that are already used in current manufacturing processes and should therefore be simple to include into a process recipe. Some material properties, such as resistivity and reliability, still need to be tested and optimised experimentally. This study also allowed us to determine the limitations of the different Cu models used and the information they can provide about the thin film morphology. Combined with insights on the effect of dopant ionic radius on the thermal stability of the material, we present a more computationally efficient approach to predicting the thin film morphology compared to our work in reference , which is useful for understanding growth morphology at material interfaces.