Abstract
Very low 0.4 pJ switching energy, fast 50 ns switching time, large >1E5 retention window at 85oC, and 1E6 cycling endurance were achieved in Ni/GeOx/SrTiOy/TaN RRAM. This RRAM device has negative temperature coefficient (TC) and ruled by bulk hopping conduction mechanism that lead to potentially better distribution. This is in sharp contrast to the positive TC and randomly distributed metallic filament RRAM. Such low switching energy is necessary for large-array NAND memory application, a unique merit of this RRAM device.