Ion nitriding of Al: growth kinetics and characterisation of the nitride layer

To study the kinetics of aluminium (Al) ion nitriding, a series of experiments has been performed at fixed ion beam parameters and substrate temperatures varied from 250 to 400°C at intervals of 50°C. The nitride layers have been analysed by nuclear reaction analysis (NRA), elastic recoil detection analysis (ERDA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Depending on the experimental conditions, the nitriding kinetics are either controlled by the delivery of N ions or by the diffusion of Al atoms. Furthermore, the growth of the nitride layer is limited by poor layer adhesion. XRD analysis reveals the formation of a hexagonal AlN-phase plus a small fraction of the cubic AlN-phase.