Charge storage effects in Si nanocrystals embedded in SiO2 thin films

This work presents the preliminary electrical characterization of Metal-Oxide-Semiconductor capacitors with high dose Si-implanted gates oxides for non-volatile memory applications. The current-voltage characteristics measured under accumulation conditions have been interpreted in terms of a Fowler-Nordheim tunneling. A strong lowering of the Fowler-Nordheim barrier is observed in the implanted devices, in relation to the reference not implanted MOS structure, which can be related to tunneling of carriers towards the ion beam synthesized nanocrystals. Direct tunneling towards/from nanocrystals is likely also responsible of the memory effects observed in these devices from the reversible shift of the high frequency capacitance-voltage characteristics after a constant voltage stress. These data corroborate the viability of the studied structures for the development of non-volatile memory devices.