The diffusion of B, following ultra low-energy implantation (500eV) was investigated. It was well known that reducing the implantation energy was an effective way to eliminate transient enhanced diffusion due to an excess of interstitials arising from implantation. The diffusion remained enhanced for sub-keV B implantation. This enhancement was linked to the presence of a silicon boride layer, located at the Si surface, which created interstitials. This phenomenon was termed B-enhanced diffusion. The latter effect was of interest since it counteracted the advantage obtained by reducing the ion implantation energy. For this reason, an investigation was made of the diffusion of low-energy B implanted into crystalline Si. A simulation program took account of the effect of B precipitation and of the effect of the silicon boride layer as a source of self-interstitials.

Modelisation of Boron Diffusion from Ultra-Low Energy Implantation in Crystalline Silicon. L.Ihaddadene-Le Coq, J.Marcon, A.Dush-Nicolini, K.Masmoudi, K.Ketata: Physica B, 2003, 340-342, 777-9