All-2D vertical metal-semiconductor field-effect transistor with sub-10 nm channel and contact lengths

Two-dimensional (2D) materials are promising candidates for next-generation nanoelectronics in the post-Moore era. However, simultaneously scaling the channel length (L_ch) and contact length (L_c) in transition metal dichalcogenide-based field-effect transistors remains a challenge. Here, we introduce an all-2D vertical metal-semiconductor field-effect transistor featuring an MoS₂ channel that contacts the sidewall of a graphene (source)-hBN (insulator)-graphene (drain)-hBN (insulator) heterostructure. A self-aligned TiS₂-MoS₂ Schottky junction ensures full-gate control over the channel. The L_ch and L_c are determined by the thicknesses of the bottom hBN and the graphene electrodes, respectively. Consequently, the L_ch and L_c can be simultaneously scaled to sub-10 nm with a vertical pitch size of sub-30 nm. The typical device exhibits an on/off ratio > 10⁷ at an operating voltage of ~0.5 V, a subthreshold swing of ~62 mV/Dec, a drain-induced barrier lowering of ~33 mV/V, and an on-state current density of ~144 μA/μm at 1 V. Sentaurus technology computer-aided design simulations further verify the good electrostatic control provided by the full-gate configuration and the bottleneck-free transport within the channel. These results highlight the potential of 2D materials for high-density and low-power integrated circuits.