Diffusion modelling of low-energy ion-implanted BF2 in crystalline silicon: Study of fluorine vacancy effect on boron diffusion

We have investigated and modelled the diffusion of boron implanted into crystalline silicon in the form of boron difluoride BF2+. We have used published data for BF2+ implanted with an energy of 2.2 keV in crystalline silicon. Fluorine effects are considered by using vacancy-fluorine pairs which are responsible for the suppression of boron diffusion in crystalline silicon. Following Uematsu's works, the simulations satisfactory reproduce the SIMS experimental profiles in the 800–1000 °C temperature range. The boron diffusion model in silicon of Uematsu has been improved taking into account the last experimental data.