The AlN films were deposited in a Picosun R-200 ALD system with a base pressure of 400 Pa and continuous N2 (99.999 %, further purified with a getter filter to remove moisture) flow through the deposition chamber. The chamber walls and the substrate holder were heated using separate heating systems. Si (100) wafers without further cleaning were cut into 15x15 mm 2 pieces and used as substrates. The substrates were loaded into the deposition chamber without using a load-lock. Commercially available TMA (Pegasus Ltd, Alpha grade) in a stainless-steel bubbler was used at room temperature with 100 sccm N2 as carrier gas. NH3 (AGA/Linde, 99.999 %) was used as the nitrogen source in the process. The TMA pulse time was set at 0.1s with 6s purge and the NH3 pulse time was set to 12s with 6s purge if nothing else is stated. H2 (99.999 %, further purified with a getter filter to remove moisture), N2 or Ar (99.999 %, further purified with a getter filter to remove moisture) was used as a cleaning pulse between the TMA and NH3 pulse. It should be noted that the flow of these cleaning pulses (150 sccm) was perpendicular to the substrate surface compared to horizontal for the purge pulses. The difference between the cleaning pulse and the purge, beside the flow direction, is also the flow rate where the purge gas (N2) had a total flow of 500 sccm (continuous flow into the reaction chamber) distributed over the six precursor gas channels, were five gas lines had a flow of 60 sccm and one line, acting the main N2 line into the chamber, had a flow of 200 sccm. While the cleaning pulse had a flow of 150 sccm independent of which gas was used and the plasma gas channel was used located above the chamber.