Figure shows the mass spectra collected when both the precursors were pulsed into the ALD reactor. The main m/z signals detected from the ALD reactor were 2, 14, 15, 16,17, 18, 20, 28, and 40, attributed to H2, N, NH, NH2, NH3, Ar 2+ , H2O, N2, and Ar, respectively. Notably, no other species were detected beyond m/z= 50. We note a problematic situation in that the m/z 28 peak can be attributed to both N2 + , which is used to constantly purge all lines in the ALD reactor, and C2H4 + , which is the expected reaction product of β-elimination of the ethyl groups from TEG. The peak at m/z = 30, attributed to C2H6, i.e., a protonated ligand appears solely when the reactants are injected into the ALD chamber, indicating that it is likely a surface reaction product. The peak observed around m/z= 29, attributed to an ethyl group C2H5, was significantly more intense when the precursors were introduced into the reactor, meaning it could emanate from precursor decomposition or surface reactions. We note that m/z = 29 is also reported as a decomposition product of C2H6 in mass spectrometry, albeit with a reported intensity lower than that for m/z = 30 , i.e., the opposite relation than in both when TEG and NH3 plasma were introduced into the chamber (Fig. ). This indicates the elimination of ethyl ligands during both precursor pulsing times. This is contrasted by the m/z= 30 signal, which spikes only during the NH3 plasma, except when the temperature is 400 °C. This indicates that the hydrogen radicals produced in the ammonia plasma The thermal ALD process showed a different trend for m/z = 29 compared with the plasma process. No m/z = 29 signal was detected when ammonia was introduced into the reactor, whereas the intensity of the signal increased significantly when the TEG was pulsed at 300 and 400°C (Fig. ). The m/z = 30 signal showed similar results in the thermal and plasma processes with a spike only during the NH3 pulse (Fig ).