Memory effect in MIS structures with amorphous silicon nanoparticles embedded in ultra thin SiOxSiOx matrix

Metal/SiO2SiO2/a-Si-SiOxSiOx/c-Si structures containing amorphous silicon nanoparticles (a-Si NPs) embedded in ultra thin SiOxSiOx matrix are fabricated by thermal evaporation of SiOxSiOx and sputtering of SiO2SiO2 layers followed by thermal annealing at 700∘C. A memory effect, due to charging of a-Si NPs in SiOxSiOx, is observed. The processes of NP charging and discharging are accomplished by applying pulses with alternative polarities. The observed shift of the flat band voltage of the high-frequency C–V curve caused by a voltage pulse of -15V having duration of 1 s is more than 3 V. In addition, the structures show good retention characteristics which make them promising for application in non-volatile memory devices.