It was found that As and B diffusion in 90nm-thick Si on SiO2, Si on insulator, samples was reduced, by ~20%, with respect to that of bulk Si for thermal processing in a lamp-based system. In contrast, when annealing was performed in a hot-wall furnace system and sample heating was determined by conduction diffusion length in Si–SiO2–Si samples was very similar to that occurring in bulk-Si reference samples. It was demonstrated that diffusion in Si–SiO2–Si multilayer structures was primarily determined by an increased sample reflectivity, generated by the presence of the buried Si/SiO2 interface that reduces the amount of heat absorbed by the sample, rather than by the enhanced recombination of point defects at this interface. The latter phenomenon was not ruled out but plays a less relevant role in determining the measured reduction of diffusion.

Role of the Si/SiO2 Interface during Dopant Diffusion in Thin Silicon on Insulator Layers. G.Mannino, A.La Magna, V.Privitera, D.Giubertoni, M.Bersani: Journal of Applied Physics, 2006, 100[9], 096112 (3pp)