A nonvolatile memory capacitor based on Au nanocrystals with HfO2 tunneling and blocking layers

We report on a nonvolatile memory capacitor based on gold nanocrystals serving as charge storage elements located between two HfO2 films acting as the tunneling and control layers. The capacitor has an equivalent oxide thicknesses of 7 nm and exhibits a large hysteresis in the C-V characteristics of 1 and 9 V for gate voltage sweeps of ±1 and ±7 V, respectively, with no frequency dependence in the range of 10 kHz to 1 MHz. The storage charge density is ∼1.2×1013 cm−2 and the flat band voltage shift is stable for write/erases operations with a voltage swing of ±5 V for over 18 h.