Therefore, in low-temperature ALD utilizing TDMAA, it is important to consider possible reactions in the gas phase or on the surface that could result in the formation of MMI since MMI should be reactive towards the surface. The signal at m/z = 18 is assigned to H2O + , residual water vapor could be present in the reactor chamber given its background pressure of 4 hPa or introduced with the TDMAA precursor which was loaded in a stainless-steel container in a glove box but inserted in the ALD reactor in air. This handling could expose the TDMAA briefly to air. Although mass spectrometry data predominantly show DMA as a major product from the ligand, distinguishing between gas phase decomposition reactions and surface reactions poses a challenge.