It was recalled that previous work on thermally induced As deactivation in highly-doped samples had proved the generation of vacancies and had suggested that the formation of As-vacancy clusters was the deactivation mechanism. By using positron annihilation spectroscopy in the 2-detector coincidence geometry, it was shown here that the thermally generated vacancies were indeed surrounded by As atoms. The results strongly confirmed the suggestion that electrical deactivation of As was indeed caused by the formation of AsnSi4-n-Vac complexes.

U.Myler, P.J.Simpson, D.W.Lawther, P.M.Rousseau: Journal of Vacuum Science and Technology B, 1997, 15[3], 757-9