Sputtering deposition of aluminium nitride on silicon

AlN films were deposited by reactive sputtering deposition on a silicon wafer using an Al target in the presence of N-2. The deposition was conducted at varying gas flux ratios (3:1 to 1:3) of N-2 to Ar. The codeposition and the binding state between Al and nitrogen were identified with Auger depth profile and x-ray photoelectron electron spectroscopy (XPS), respectively. The binding energy between nitrogen and Al elements was enhanced at lower N-2:Ar ratios of less than 1:1. AlN was not detectable with GID (Glazing Incident x-ray Diffraction) at N-2 to Ar ratios of 1:1 and above. Heating of the substrate at 200 degrees C and a lower working pressure enhanced the crystallization of ALN films. A broadened diffraction peak was achieved with GID for films deposited at a N-2:Ar ratio of as high as 3:1 when operated at a low working pressure.