The influence of the buried Si/SiO2 interface in Si-on-insulator substrates, upon B electrical activation, was investigated by comparing experimental data and atomistic simulations in bulk Si and Si-on-insulator materials. In crystalline Si, the effect of the Si/SiO2 interface upon the formation of B clusters was essentially negligible because they were formed rapidly and locally in the region with high B and Si interstitial concentrations. Only during post-implant annealing did a slight acceleration of B activation occur, as the Si/SiO2 interface increased the removal of Si interstitials and facilitated B cluster dissolution. In pre-amorphized Si, B clusters formed during re-growth. Therefore, the effect of the Si/SiO2 interface was mainly related to its influence upon end-of-range defect evolution after re-growth which, in turn, affected B de-activation and reactivation. Thus, slightly less B deactivation occurred in Si-on-insulator as compared to bulk Si as the Si/SiO2 interface accelerated end-of-range defect dissolution. The effect was more significant when the end-of-range damage was closer to the Si/SiO2 interface.

Boron Diffusion and Activation in SOI and Bulk Si - the Role of the Buried Interface. M.Aboy, L.Pelaz, J.Montserrat, F.J.Bermúdez, J.J.Hamilton: Nuclear Instruments and Methods in Physics Research B, 2007, 257[1-2], 152-6