Graphene Nanoplatelets Embedded in HfO2 for MOS Memory

Abstract

In this work, a MOS memory with graphene nanoplatelets charge trapping layer and a double layer high-κ Al<inf>2</inf>O<inf>3</inf>/HfO<inf>2</inf> tunnel oxide is demonstrated. Using C-V<inf>gate</inf> measurements, the memory showed a large memory window at low program/erase voltages. The analysis of the C-V characteristics shows that electrons are being stored in the graphene-nanoplatelets during the program operation. In addition, the retention characteristic of the memory is studied by plotting the hysteresis measurement vs. time. The measured excellent retention characteristic (28.8% charge loss in 10 years) is due to the large electron affinity of the graphene. The analysis of the plot of the energy band diagram of the MOS structure further proves its good retention characteristic. Finally, the results show that such graphene nanoplatelets are promising in future low-power non-volatile memory devices.