As argued in our previous study, the addition of a reactive pulse (hydrogen plasma, hydrogen gas, and argon plasma) in between the precursor pulses improved the film quality and suggested to improve the removal of the ethyl ligands at an optimal temperature of 320°C during the plasma process. We used mass spectrometry to test this hypothesis and tracked the same m/z ratios 29 and 30 in Fig. . The results show surprisingly no significant peaks when the extra pulses were introduced into the chamber, except for a slight increase in the peak signal for m/z = 29 with the hydrogen gas pulse, but lost intensity with time. Thus, we suggest that the B pulse does not favor ethyl elimination. Instead, we speculate that the observed increase in GPC in our previous study is attributed to the B-pulse preparing the surface for subsequent nitridation by providing more time for the formation of more reactive or less sterically hindered intermediate(s).