Dose, energy, and ion species dependence of the effective plus factor for transient enhanced diffusion

Transient enhanced diffusion of dopants in silicon is frequently modeled us ing the "+ 1" approximation of implantation damage. Using a more realistic model predicts somewhat more transient diffusion than the +1 model. For man y purposes, the +1 model can be improved by a simple scaling factor, which we call the effective plus factor. In this work we study the dose, energy, and ion species dependence of the effective plus factor. The simulation mod el is based on binary collision simulations to obtain point defect concentr ations after ion implantation and a continuum model that includes the effec t of spatial correlations of the defects to describe diffusion and recombin ation. This approach is shown to agree well with atomistic simulations. Res ults are presented in the energy range of 1 keV to 1 MeV, for doses between 0 and 3 x 10(14) cm(-2) and the ion species B, Si, P, and As. In the high- dose limit deviations from the +1 model are considerable for heavy ions and /or low energies with a maximum of approximately 4 for 1 keV As. The plus f actor also increases with decreasing dose. However, the increase is not sig nificant for doses above 10(13) cm(-2) and only moderate (less than a facto r of two) for doses above 10(12) cm(-2). The results agree with transient e nhanced diffusion data over a range of energies and doses, with some anomal ous exceptions at very low dose. (C) 2000 The Electrochemical Society. S001 3-4651(99)11-065-6. All rights reserved.