Atomically\nPrecise Graphene Nanoribbon Transistors\nwith Long-Term Stability and Reliability

Atomically precise\ngraphene nanoribbons (GNRs) synthesized from\nthe bottom-up exhibit promising electronic properties for high-performance\nfield-effect transistors (FETs). The feasibility of fabricating FETs\nwith GNRs (GNRFETs) has been demonstrated, with ongoing efforts aimed\nat further improving their performance. However, their long-term stability\nand reliability remain unexplored, which is as important as their\nperformance for practical applications. In this work, we fabricated\nshort-channel FETs with nine-atom-wide armchair GNRs (9-AGNRFETs).\nWe revealed that the on-state (<i>I</i><sub>ON</sub>) current\nperformance of the 9-AGNRFETs deteriorates significantly over consecutive\nfull transistor on and off logic cycles, which has neither been demonstrated\nnor previously considered. To address this issue, we deposited a thin\n∼10 nm thick atomic layer deposition (ALD) layer of aluminum\noxide (Al<sub>2</sub>O<sub>3</sub>) directly on these devices. The\nintegrity, compatibility, electrical performance, stability, and reliability,\nof the GNRFETs before and/or after Al<sub>2</sub>O<sub>3</sub> deposition\nwere comprehensively studied. The results indicate that the observed\ndecline in electrical device performance is most likely due to the\ndegradation of contact resistance over multiple measurement cycles.\nWe successfully demonstrated that the devices with the Al<sub>2</sub>O<sub>3</sub> layer operate well up to several thousand continuous\nfull cycles without any degradation. Our study offers valuable insights\ninto the stability and reliability of GNR transistors, which could\nfacilitate their large-scale integration into practical applications.