The diffusion process and the absolute sputter yields in the system aluminum-nitrogen are investigated for nitrogen implantation in aluminum at elevated temperatures. using plasma immersion ion implantation. The substrates are thin aluminum layers deposited on silicon by vacuum arc deposition. The advantages of these layers are (i) easier preparation for transmission electron microscopy (TEM) investigations and (ii) the exact measurement of the atomic area densities before and after implantation. Nitrogen extending into the material a few hundred nanometers was observed at 485 degreesC using energy filtered TEM, albeit the diffusing species are Al cations. Holes occurring at the Al/Si interface support this viewpoint. The alternative explanation of Al diffusion into Si can be excluded. In sputter saturation with a. N/Al ratio of 1: 1 at the surface, a preferential sputtering of nitrogen compared to aluminum with respective sputter yields of I and 0.3 +/- 0.1 was found using Rutherford backscattering spectrometry. (C) 2003 American Vacuum Society.