An investigation was made of the effect of deep F+ implantation upon the B diffusion. The effects upon B thermal diffusion and transient enhanced diffusion were studied separately by characterizing the diffusion of a buried B marker layer in wafers with, and without, a 185keV F+ implantation to 2.3 x 1015/cm2 or with, and without, a 288keV P+ implantation to 6 x 1013/cm2. In samples which were given both implants, F completely eliminated the transient, enhanced the B diffusion caused by the P+. In samples which were implanted with only F+, the F suppressed B thermal diffusion by 65%. This was explained by the effect of the F upon the vacancy concentration in the vicinity of the B profile.

Reduction of Boron Thermal Diffusion in Silicon by High Energy Fluorine Implantation. H.A.W.El Mubarek, P.Ashburn: Applied Physics Letters, 2003, 83[20], 4134-6