Measurement of sputtering yields induced by molecular nitrogen bombardment of aluminum

Several authors have shown recently that is is possible to synthesize aluminum nitride (AlN) by direct nitrogen implantation into aluminum. The AlN layer has already been characterized (depth profiling, phase formation, etc.) by means of several techniques including Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), nuclear reaction analysis (NRA) and Rutherford backscattering spectrometry (RBS). However, no data about sputtering yields during molecular and atomic nitrogen implantation into aluminum are currently available. The aim of this work is to measure the aluminum and nitrogen sputtering yields of evaporated thin aluminum films (4000 A) on carbon, bombarded with 100 keV 15N2+ at doses ranging from 5x1016 to 1.5x1018 N2+/cm2. We have used nuclear reaction analysis (NRA), Rutherford backscattering spectrometry (RBS) and quartz-crystal microbalance techniques. We have compared our data with those obtained by two models: transport of ions in matter (TRIM) and TRIM-dynamic (TRIDYN). Additionally, an attempt is made to determine the Al and N component sputtering yields within the resolution of the applied techniques. It is shown that the sputtering yields strongly depend on the contamination of the sample surface. (orig.)