High-temporal-resolution characterization reveals outstanding random telegraph noise and the origin of dielectric breakdown in h-BN memristors

Memristor-based electronic memory have recently started commercialization, although its market size is small (~0.5%). Multiple studies claim their potential for hardware implementation of artificial neural networks, advanced data encryption, and high-frequency switches for 5G/6G communication. Application aside, the performance and reliability of memristors need to be improved to increase their market size and fit technology standards. Multiple groups propose novel nano-materials beyond phase-change, metal-oxides, and magnetic materials as resistive switching medium (e.g., two-dimensional, nanowires, perovskites). However, most studies use characterization setups that are blind to critical phenomena in understanding charge transport across the devices. Here an advanced setup with high temporal resolution is used to analyze current noise, dielectric breakdown growth, and ambipolar resistive switching in memristors based on multilayer hexagonal boron nitride (h-BN), one of the most promising novel nano-materials for memristive applications. The random telegraph noise in pristine memristors and its evolution as the devices degrade, covering ~7 orders of magnitude in current with consistent observation, is studied. Additionally, an ambipolar switching regime with very low resistance down to 50Ω and its connection with a telegraph behavior with high/low current ratios >100, linked to a thermally-driven disruption of a metallic nanofilament, is shown. (© 2023 Wiley‐VCH GmbH)