Charge storage effect of the vertically stacked InAs nanodots embedded in Al/sub 0.5/Ga/sub 0.5/As matrix

This report describes the memory effect of an Al/sub 0.5/Ga/sub 0.5/As/GaAs field-effect (FE) structure which contains vertically aligned InAs nanodots in the barrier layer. The FE structure is grown by molecular beam epitaxy using Stranski-Krastanow islands as the nanodots. Charge storage effect of the nanodots is analyzed by a capacitance-voltage measurement and resulted in a hysteresis loop due to the stable electron trapping at nanodot potentials. The amount of charge for the long-term memory retention at 300 K is estimated to be /spl sim/14 nC/cm/sup 2/, which is promising for memory device applications of the FE structure.