Scanning spreading resistance microscopy of two-dimensional diffusion of boron implanted in free-standing silicon nanostructures

B implants of $1\mathrm{keV}$ , $1\times {10}^{15}\mathrm{at.}{\mathrm{cm}}^{-2}$ into $125\text{-}\mathrm{nm}$ -wide, free-standing Si nanostructures have been characterized using scanning spreading resistance microscopy following a $0\mathrm{s}$ , $1050°\mathrm{C}$ anneal in ${\mathrm{N}}_2$ . A curved diffusion front has been observed. B in the center of the ridge diffuses further than at the sides. A similar effect has been observed in SUPREM-IV simulations. It is attributed to a reduction in transient enhanced diffusion close to the vertical surfaces due to recombination of ion-implantation-induced excess Si self-interstitials.