Memory effect in Si nanocrystal embedded SiO2 films

We report on a memory effect in SiO₂ films containing Si nanocryslals (nc-Si). The devices consist of MOS structures with nc-Si embedded throughout the gate oxide. With charge transport in nc-Si both by constant voltage application and constant current application, the MOS devices can be switched from one state to another slate The stale switchings can be observed in time domain current, voltage, and MOS capacitance measurements. The modification in current conduction can be explained in terms of the formation/breaking of tunneling paths due to charge trapping/detrapping in nc-Si, while the the capacitance modifications are attributed to the changes of nc-Si contribution in MOS capacitance due to charge trapping/detrapping in nc-Si. The modulation of MOS electrical states by charging/discharging in nc-Si provides the possibility of a new type of memory devices application.