It was recalled that current experiments and diffusion models indicated that, during annealing, implanted N diffuses towards the surface. The mechanism proposed for N diffusion was the formation of N-vacancy complexes in Si, as indicated by previous ab initio studies. However, to date, there does not exist any experimental evidence of N-vacancy formation in Si. This letter provides experimental evidence through positron annihilation spectroscopy that N-vacancy complexes indeed form in N implanted Si, and compares the experimental results to the ab initio studies, providing qualitative support for the same.

Experimental Identification of Nitrogen-Vacancy Complexes in Nitrogen Implanted Silicon. L.S.Adam, M.E.Law, S.Szpala, P.J.Simpson, D.Lawther, O.Dokumaci, S.Hegde: Applied Physics Letters, 2001, 79[5], 623-5