Depth profiling of nitrogen implanted into Si/C and Zr/C bilayers with nuclear reaction analysis

In order to study the behavior of implanted nitrogen into Zr/carbon and Si/carbon bilayers, depth profiles of 15N and 14N were measured using the nuclear reaction of 15N(p,αγ)12C and 14N(3He,α)13N, respectively. The measured depth profiles were compared with the calculated profiles obtained by Monte Carlo simulation using dynamic-SASAMAL assuming a 25 at.% saturation for nitrogen concentration in carbon. Single 15N implantation and alternate implantation of 15N and 14N were performed at RT and at 700 deg. C, with and without annealing. For depth profiling of the other elements, RBS was used and the chemical state was analyzed by XPS with Ar sputtering. The depth profiles of implanted nitrogen in Zr (60 nm)/glassy carbon (GC) showed nitrogen diffusion from the GC layer to the upper Zr layer. The depth profiles of the implanted nitrogen in Si/GC and Si/diamond-like carbon (DLC) agreed with the SASAMAL results assuming 40 at.% saturation for N in Si. The depth profile of 15N (1x1017 cm-2) which was implanted into Si/DLC after 14N (4x1017 cm-2) implantation did not agree with the calculated result but were almost the same as the profiles of 14N (4x1017 cm-2) except for the concentration level. And half of the 15N were lost during the annealing at 700 deg. C, 1 h, keeping the same depth profile. The annealing behavior of the first implanted 14N was the same as the 15N