AlN growth from TDMAA and NH3, is likely similar to the much more researched TDMAT and NH3 for ALD of TiN. We therefore did thermal-and plasma ALD experiments with TDMAT for comparisons to TDMAA. From the mass spectra in Fig. ) and Fig. ), we note prominent peaks around m/z = 44 signalling DMA as well as m/z = 16, 27, 29 and 30 which we also identified in the TDMAA-NH3 process. Looking at how TDMAT and TDMAA compare in the mass spectra, we believe that the reaction mechanisms for TDMAA are the same or at least very similar to the ones for TDMAT. In literature , TDMAT has been suggested to decompose and react through an insertion-elimination reaction or a hydrogenation reaction leading to a transamination exchange, consisting of an attack on the Ti centre of TDMAT by the N lone electron pair of ammonia (H2N-H). This reaction is characterized by elimination of -N(CH3)2 ligands at m/z = 44 or 45 (as dimethylamine) and insertion of ammonia (as NH2) where a proton is transferred to a dimethylamido group, which leaves as dimethylamine. As was observed in TDMAA, complex surface reactions and intermediates do take place in TDMAT-NH3 process as well, including the release of methane (m/z = 16) and signals at m/z = 27 and 30. However, the outstanding question at this point is the source of nitrogen in the deposited AlN films. There are two possible sources: TDMAA and NH3. It is also important to note that results of TiN deposition with TDMAT and NH3 as precursors, from isotopic labelling studies have concluded that all of the N in a 'clean' TiN thin film is derived from NH3 via an intermolecular process which facilitates transamination. We believe this could be the case as well for the TDMAA-NH3 process, even though mass spectrometric results alone cannot drive us towards that same conclusion.