Samples were doped with Si to a concentration of about 2.7 x 1018/cm3 and were annealed (800 to 1000C, 3 to 20h) under As-rich or As-poor conditions. The Si out-diffusion was measured by using the capacitance-voltage method and an electrochemical profiler. It was found that the Si diffusivity exhibited a marked dependence upon the As4 vapour phase pressure and upon the electron concentration. When reduced to intrinsic conditions, activation enthalpies of 3.91 and 4.19eV were obtained for As-rich and As-poor annealing conditions, respectively. On the basis of these results, it was concluded that Si out-diffusion was governed by the triply negatively charged vacancies, VGa3-.

H.M.You, U.M.Gösele, T.Y.Tan: Materials Science Forum, 1993, 117-118, 399-404