Lattice location and atomic mobility of implanted boron in silicon

Abstract

Abstract A unifying interpretation is presented for a number of different studies concerned with the lattice location and diffusivity of boron implanted into silicon. It is suggested that the nonsubstitutional boron present after a room temperature implantation consists mostly of boron-vacancy complexes, together with a relatively small number of boron interstitials. The boron interstitials anneal at 200–300°C without long-range migration, whereas the boron-vacancy complexes are thermally very stable (possibly due to an extended defect configuration) and anneal to produce substitutional boron atoms only at high temperatures where silicon self-interstitials take over as the dominant intrinsic point defect. This model explains numerous experimental observations in a manner which both reconciles a number of apparent conflicts between different types of experiment, and is consistent with an interstitial mechanism for self-and boron diffusion in silicon at high temperatures: