COPPER CLUSTERS MADE BY IMPLANTATION IN ALUMINUM NITRIDE

Copper has been implanted in AlN at 80 and 300 K with an average concentration around 14%. X-ray absorption spectroscopy performed at the K edge of Cu on as-implanted samples and on samples annealed at 800 degrees C for 1 and 5 h show that Cu precipitated in the host matrix even for implantations performed at low temperature. Analysis of the spectra allows the average size of the clusters to be deduced. These crystalline entities grow with dense planes of each phase parallel to each other, as shown from previous transmission electron microscopy experiments. The initial implantation fluence together with the subsequent annealing times and temperatures appear to be easy tools to monitor the cluster size.