Nonpolar Resistive Switching of Multilayer-hBN-Based Memories

Resistive switching (RS) induced by electrical bias is observed in numerous materials, including 2D hexagonal boron nitride (hBN), which has been used in resistive random access memories (RRAMs) in recent years. For practical high-density, cross-point memory arrays, compared with bipolar memories, nonpolar (or unipolar) devices are preferable in terms of peripheral circuit design and storage density. The non-volatile nonpolar RS phenomenon of hBN-based RRAMs with Ti/hBN/Au structure as a prototype is reported. Stable manual DC switching for approximate to 10(3) cycles with an average window over five orders of magnitude is demonstrated. After identifying a possible mechanism related to the Joule heat that contributes to the rupture of conductive filaments in nonpolar RS operations, this mechanism is validated by analyzing the occurrence of the "Re-set" process. Though the intriguing physical origin still requires more comprehensive studies, the achievement of nonpolar RS should make it more feasible to use hBN in practical RRAM technology.