Copper films were deposited using Copper (II) hexafluoroacetylacetonate (Cu(hfac)₂) or Copper(II) acetylacetonate (Cu(acac)₂) as precursors, with plasma electrons as reducing agents. A detailed description of the principles behind e-CVD and an e-CVD system setup, along with general experimental procedures is provided elsewhere. For this study, the experiments were conducted in a lab-built 150 mm diameter stainless-steel vacuum chamber with a base pressure of 6 Pa, equipped with a stainless-steel showerhead hollow cathode plasma source built by Meaglow, as detailed in Fig. . An argon plasma was generated using a flow of 100 sccm Ar through the hollow cathode. The plasma was ignited by an Advanced Energy MDX500 DC power supply, and the plasma power was varied in the range 20 to 200 W. Cu(hfac)₂ and Cu(acac)₂, were kept in a stainless-steel evaporator and sublimed at 40°C and 90 °C, respectively at 50 Pa. The evaporator was purged with argon gas at a flow rate of 10 sccm and the gas line was heated to 70 °C and 110 °C, respectively to avoid condensation.