Role of oxygen contaminant on the physical properties of sputtered AlN thin films

The paper deals with the role of the oxygen contamination, coming from residual gas atmosphere in the deposition chamber, on the physical properties of AlN thin films, sputtered in Ar + N2 working gas, at different values of nitrogen flux percentages, and without substrate heating. Contaminant concentration varies with the nitrogen partial pressure in the working gas mixture. Oxygen atoms are incorporated into the growing films due to their higher affinity towards Al atoms compared to N atoms. Oxygen inclusion produces important modifications in the structural, chemical, optical and electrical properties of the AlN thin films. Therefore, contamination can play a crucial role for the tuning of the physical characteristics of sputtered materials. [Display omitted] •AlN thin films were produced by RF magnetron sputtering.•The role of oxygen contamination was investigated.•Oxygen incorporation can be varied by changing N2 content in the reactive mixture.•Oxygen influences structural, morphological, optical and electrical properties.•Contamination plays a nodal role for tuning films physical characteristics.