Neon retention in tungsten, boron and mixed thin-films under the effects of thermal annealing studied by isotopic tracing

• Neon retention was studied using isotopic tracing by implantation of 20 Ne & 22 Ne. • Neon retention is stable in W, B and mixed W-B thin-films to 1000 °C. • No diffusion, intermixing or desorption of Ne-isotopes observed in any composition. • No effect depending on substrate type (W or Si) was observed. The retention of two neon isotopes, 20 Ne and 22 Ne, was studied by ion beam analysis (IBA) for thin-films of mixed W and B as well as for pure W and B layers grown on silicon-and tungsten-substrates by means of magnetron sputter deposition. Each isotope was implanted to a fluence of 3 × 10 16 at./cm 2 but at different energies (35–190 keV) to obtain deposition profiles closer to the surface and deeper into the film, depending on isotope and thin-film composition. Thermal annealing in combination with IBA was used to investigate the Ne-retention in a range of temperatures between RT and 1000 °C. Time-of-flight elastic recoil detection analysis was employed to monitor the retention and depth profiles of the Ne isotopes. Both Ne-isotopes remain at their original implantation depth, thus not indicating diffusion, intermixing or desorption for the full range of temperatures and for all studied compositions.