Fig. . shows the QCM frequency shift per deposition cycle as a function of time for the copper precursor pulse, the plasma electron pulse, and the purge time between the pulses. The curves in Fig. suggest that a saturation in film deposition per cycle is reached for precursor and plasma pulses longer than 5 s, and purge times exceeding 20 s. Since such saturation curves are used to demonstrate a self-limiting surface chemistry in ALD processes, we interpret Fig. as a self-limiting surface chemistry in the e-CVD process and thus that the process can be described as an e-ALD process. To further study the precursor adsorption and the growth behaviour during the time-resolved e-CVD process, extended pulse durations of Cu(hfac)2 precursor, longer argon purge intervals, and prolonged plasma exposure were employed. Cu(hfac)2 was pulsed into the reactor for 30 s, followed by 60 s argon purge and 20 s of plasma exposure. The plasma discharge power was set to 20 W, and the substrate bias was set to +60 V. The detailed QCM trace of this deposition cycle is given in Fig. . We note that the mass gain during precursor exposure is high in the early stage of the precursor pulse, indicating formation of a monolayer (Fig. ). This is followed by a slower mass gain after about 5 s, suggesting formation of multilayers of the precursor. Keep in mind that the QCM sensor was maintained at 50 °C, meaning that some condensation likely occurs as the Cu(hfac)2 was evaporated at 40 °C. We also note from the mass evolution trace that the mass decreased to the level of the expected monolayer during the argon purge (Fig. ), suggesting that the precursor multilayer can be purged away with long enough argon purge. We note that the QCM trace in Fig. suggest that the monolayer is formed after about 5 s, which aligns with the time for saturation for the Cu(hfac)2 pulse in Fig. . The time needed to purge away the multilayer, about 40 s (Fig. ), also aligns with the time needed for saturation of the Ar purge suggested in Fig. .