STUDY OF NITROGEN DISTRIBUTIONS IMPLANTED AT HIGH-TEMPERATURE INTO ALUMINUM

Nuclear reaction analysis is a powerful tool for the study of nitrogen implantation into aluminum. Previously this technique was used for studying the depth distributions of molecular nitrogen implanted in aluminum at 100 keV to different doses, but at temperatures below 400-degrees-C. The aim of the current work is to study the processes involved when nitrogen is implanted at the same energy but at higher temperatures, between 400 and 550-degrees-C. It is found that at these temperatures, a nitrogen surface peak is present in the aluminum. In addition, the chemical bonding of nitrogen atoms with the aluminum matrix has been investigated by low energy electron induced X-ray spectroscopy (LEEIXS), which confirmed the formation of aluminum nitride at low implantation doses. The distribution of the C, O, N-14 and N-15 atoms at the surface has been measured by secondary ion mass spectroscopy (SIMS). It was found that the nitrogen surface peak is located close to the contaminated layer, which can be explained by nitrogen diffusion from the bulk to the surface followed by a precipitation in that region.