Direct observation of two-dimensional diffusion of the self-interstitials in crystalline Si

The two-dimensional (2D) diffusion of Si self-interstitials (I) from a submicron laterally confined source has been investigated in detail. High-resolution scanning capacitance microscopy was used for quantitative measurements of the B transient enhanced diffusion induced by the I flux generated by a low-energy Si implantation through a submicron dimension oxide mask. We show that the I depth penetration strongly depends on the original lateral size of the source. The 2D I diffusion has been well described by a 2D rate equations model, using the same physical parameters valid for one-dimensional diffusion.