Structural properties of Al2O3/AlN thin film prepared by magnetron sputtering of Al in HF-activated nitrogen plasma

A process for ion-plasma formation of aluminum nitride (AlN) nanolayers on nitrided sapphire (Al2O3) substrates is presented. The method is based on the direct current magnetron sputtering of a high-purity aluminum target in the presence of an argon–nitrogen gas mix and high frequency-activated nitrogen plasma. The method, combined with ion etching, produced matched layers by nitration of Al2O3 in the (0001) plane, and formation of high quality AlN epilayers on this surface was observed. The processing characteristics and morphology dependence on synthesis parameters were studied using atomic force microscopy.

► Technology based on plasma processes was used.
► Сhemical composition of elements in the layers was analyzed.
► Near-surface layer was obtained on the sapphire substrate by nitridation.
► Increasing of substrate temperature stimulates the growth of layer perfection.
► Morphology is connected with growth mechanism and the structure of substrate.