The effects of low-dose implantation, with Si+, Ne+ and F+, upon the transient enhanced diffusion of B after annealing (900C, 0.5h) were investigated. The processing conditions, such as the dose (3.5 x 1013/cm2) and energy (30 to 60keV) were chosen so as to simulate the lightly doped drain implant in an 0.35μ complementary metal-oxide semiconductor device. An epitaxially grown B-doping superlattice was used to extract directly the depth profiles of the average Si self-interstitial concentration after processing. In the case of Si+, the transient enhanced diffusion of B increased with the energy of the implanted ion. When Ne+ was implanted by using the same energy as that used for Si+, it caused more transient enhanced diffusion. When Ne+ was implanted so as to have the same range as Si+, it caused slightly less transient enhanced diffusion. Implantation with F+ enhanced the B diffusivity considerably less than did Si or Ne implantation. These effects were modelled by using simulations of defect diffusion in the presence of traps. A trap concentration of 2.4 x 1016/cm3 gave good agreement in all situations except that of F+ implantation; where 6.6 x 1016/cm3 traps were necessary. It was suggested that this was caused by additional traps, for Si interstitials, that were related to F+.

H.H.Vuong, H.J.Gossmann, C.S.Rafferty, H.S.Luftman, F.C.Unterwald, D.C.Jacobson, R.E.Ahrens, T.Boone, P.M.Zeitzoff. Journal of Applied Physics, 1995, 77[7], 3056-60