HIGH-RESOLUTION DEPTH PROFILING OF NITROGEN IN A1N LAYERS

Nitrogen implantation into aluminum offers many industrial applications. It has already been observed that the shape and the thickness of the layer formed depend strongly on the implantation doses for a given energy. The aim of this work is to investigate the atomic movements of nitrogen during implantation which leads to the formation of the aluminum nitride layer. Resonant nuclear reaction analysis (RNRA) allows for the profiling of both stable nitrogen isotopes (N-15 and N-14) by means of the N-15(p,alpha-gamma)C-12 reaction at 429 keV and the N-14(alpha,gamma)F-18 reaction at 1531 keV. Therefore, 100 keV N-14(2)+ and 100 keV N-15(2)+ were alternatively implanted into aluminum, and the behavior of each isotope was followed using the appropriate nuclear reaction. The results indicate that some of the nitrogen atoms already present in the matrix are displaced and moved out the sample by the incident nitrogen atoms during the implantation. Consequently, the distribution of the original isotope is broadened due to the collisional processes occurring when nitrogen doses increase.