Ultrashort Vertical-Channel van der Waals Semiconductor Transistors

Adv Sci (Weinh). 2019 Dec 23;7(4):1902964. doi: 10.1002/advs.201902964. eCollection 2020 Feb.

Abstract

Atomically thin 2D van der Waals semiconductors are promising candidates for next-generation nanoscale field-effect transistors (FETs). Although large-area 2D van der Waals materials have been successfully synthesized, such nanometer-length-scale devices have not been well demonstrated in 2D van der Waals semiconductors. Here, controllable nanometer-scale transistors with a channel length of ≈10 nm are fabricated via vertical channels by squeezing an ultrathin insulating spacer between the out-of-plane source and drain electrodes, and the feasibility of high-density and large-scale fabrication is demonstrated. A large on-current density of ≈70 µA µm-1 nm-1 at a source-drain voltage of 0.5 V and a high on/off ratio of ≈107-109 are obtained in ultrashort 2D vertical channel FETs with monolayer MoS2 synthesized through chemical vapor deposition. The work provides a promising route toward the complementary metal-oxide-semiconductor-compatible fabrication of wafer-scale 2D van der Waals transistors with high-density integration.

Keywords: 2D nanoelectronics; ultrashort channel; van der Waals semiconductors; vertical type transistors.