Charging characteristics of Au nanocrystals embedded in metal-oxide-semiconductor structures

The charging characteristics of metal-oxide-semiconductor (p-type) structures containing Au nanocrystals in SiO2 gate oxide were studied. The Au nanocrystals of 2–3nm in diameter are self-assembled from the agglomeration of an ultrathin Au layer embedded in SiO2 matrix by annealing at 600°C. A large hysteresis loop is found in the capacitance-voltage (C-V) relation even at a low operating voltage (2V), indicating its significant charge storage effect. Different charging rates for two kinds of trapped carriers (electron and hole) were found from C-V measurement under various scan rates. The relatively stable retention characteristic for holes trapped in the Au nanocrystals at room temperature was also demonstrated.