The behavior of implanted Be was studied by annealing samples which had been implanted with low or high Be doses. The high-dose (1014/cm2) samples exhibited an increase in diffusion upon increasing the annealing temperature from 700 to 900C. However, the low-dose (2 x 1013/cm2) samples exhibited a decrease in diffusivity as the temperature increased. The temperature dependence in the low-dose case could be reversed by the co-implantation of B (1014/cm2). This behavior was explained in terms of the substitutional-interstitial diffusion mechanism and the relative concentrations of interstitial and substitutional Be atoms in the various cases.

M.D.Deal, H.G.Robinson: Applied Physics Letters, 1989, 55[10], 996-9