Herein, we report a low temperature, ALD-like, CVD approach depositing AlN using TMA and NH3 delivered in separate pulses at 480 °C. We show that adding an extra gas pulse, with the gas flow perpendicular to the substrate surface between the TMA and NH3 pulses, leads to a drastic decrease in C content and increases the crystalline quality of the films. Quantumchemical density functional theory and kinetic modelling suggest that the lower carbon content in the films is attributed to the prevented re-adsorption of desorbing methyl groups to the AlN surface.