Irreversible Conductive Filament Contacts for Passivated van der Waals Heterostructure Devices

摘要

2D materials with atomic-scale thickness have attracted immense interestowing to their intriguing properties, which can be useful for electronicdevices. As ultrathin 2D materials are highly vulnerable to external conditions,passivation of 2D materials is required to maintain the stability of 2D electronicdevices. However, 2D channels are embedded in passivation layers, makingthe formation of suitable contacts in passivated 2D devices challenging.Here, a novel method for fabricating irreversible conductive filament (ICF)contacts on a 2D channel passivated by hexagonal boron nitride (hBN) layersis demonstrated. Defective paths are formed in the top hBN layer of hBNencapsulatedgraphene (or MoS_2) using oxygen-plasma treatment, alongwhich ICFs are fabricated by applying repetitive bias. ICF contacts formedin the combined paths of migrated metal atoms and vacancies are stableduring device operation, which is in contrast with that the filaments in hBNmemristors are reversible. Field-effect transistors with ICF contacts exhibita low contact resistance and high stability. This study shows a new contactmethod, which has great potential for high-performance 2D electronics devices.