Reduced Multilayer Graphene Oxide Floating Gate Flash Memory With Large Memory Window and Robust Retention Characteristics

Reduced multilayer graphene (rMLG) is investigated as a charge storage layer (CSL) in conventional floating gate (FG) flash memory structure. A large memory window of 9.4 V at ±20-V program/erase and robust 10-years data retention at 150^°C is demonstrated. Significant over-erase observed in these memory devices signifies hole storage in the rMLG sheets. Fast programming and clear saturation of the program transients observed with the rMLG CSL memory devices suggest reduced ballistic transport in the plane perpendicular to the graphene. Activation energies for programmed and erased state retention losses are calculated as 1.05 and 1.11 eV, respectively. These observations establish the potential of rMLG sheets as a replacement of conventionally used polycrystalline silicon FG.